diff --git a/AssetManager.API/Program.cs b/AssetManager.API/Program.cs
index 058f981..34b9bed 100644
--- a/AssetManager.API/Program.cs
+++ b/AssetManager.API/Program.cs
@@ -64,6 +64,7 @@ builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
 builder.Services.AddDatabase();
 
 builder.Services.AddHttpClient();
+builder.Services.AddMemoryCache(); // 添加内存缓存
 builder.Services.AddScoped<AssetManager.Services.Services.WechatService>();
 builder.Services.AddScoped<AssetManager.Services.Services.JwtService>();
 builder.Services.AddScoped<AssetManager.Services.IPortfolioService, AssetManager.Services.PortfolioService>();
@@ -80,8 +81,8 @@ else
     builder.Services.AddScoped<AssetManager.Infrastructure.Services.IMarketDataService, AssetManager.Infrastructure.Services.MarketDataService>();
 }
 
-// 汇率服务：预留接口，目前用 Mock 实现
-builder.Services.AddScoped<AssetManager.Infrastructure.Services.IExchangeRateService, AssetManager.Infrastructure.Services.MockExchangeRateService>();
+// 汇率服务：真实实现，带缓存和降级机制
+builder.Services.AddScoped<AssetManager.Infrastructure.Services.IExchangeRateService, AssetManager.Infrastructure.Services.ExchangeRateService>();
 
 // 策略引擎
 builder.Services.AddScoped<AssetManager.Infrastructure.StrategyEngine.IStrategyEngine, AssetManager.Infrastructure.StrategyEngine.StrategyEngine>();
diff --git a/AssetManager.Infrastructure/Services/ExchangeRateService.cs b/AssetManager.Infrastructure/Services/ExchangeRateService.cs
new file mode 100644
index 0000000..6134ca8
--- /dev/null
+++ b/AssetManager.Infrastructure/Services/ExchangeRateService.cs
@@ -0,0 +1,135 @@
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging;
+using System.Net.Http.Json;
+
+namespace AssetManager.Infrastructure.Services;
+
+/// <summary>
+/// 真实汇率服务，接入 exchangerate-api.com 免费接口
+/// </summary>
+public class ExchangeRateService : IExchangeRateService
+{
+    private readonly HttpClient _httpClient;
+    private readonly IMemoryCache _cache;
+    private readonly ILogger<ExchangeRateService> _logger;
+    
+    // 缓存键前缀
+    private const string CacheKeyPrefix = "ExchangeRate_";
+    // 缓存过期时间：1小时
+    private const int CacheExpirationHours = 1;
+    // 基础汇率币种（用USD作为中间货币，减少API调用次数）
+    private const string BaseCurrency = "USD";
+
+    public ExchangeRateService(
+        HttpClient httpClient, 
+        IMemoryCache cache,
+        ILogger<ExchangeRateService> logger)
+    {
+        _httpClient = httpClient;
+        _cache = cache;
+        _logger = logger;
+    }
+
+    public async Task<decimal> GetExchangeRateAsync(string fromCurrency, string toCurrency)
+    {
+        _logger.LogInformation("获取汇率: {FromCurrency} -> {ToCurrency}", fromCurrency, toCurrency);
+
+        // 同币种直接返回1
+        if (fromCurrency.Equals(toCurrency, StringComparison.OrdinalIgnoreCase))
+        {
+            return 1.00m;
+        }
+
+        // 先尝试从缓存获取
+        string cacheKey = $"{CacheKeyPrefix}{fromCurrency}_{toCurrency}";
+        if (_cache.TryGetValue(cacheKey, out decimal cachedRate))
+        {
+            _logger.LogDebug("缓存命中: {Key} = {Rate}", cacheKey, cachedRate);
+            return cachedRate;
+        }
+
+        try
+        {
+            // 以USD为基础货币获取所有汇率
+            var response = await _httpClient.GetFromJsonAsync<ExchangeRateResponse>($"https://v6.exchangerate-api.com/v6/4a8a42b4b9a3c4d5e6f7a8b9/latest/{BaseCurrency}");
+            
+            if (response == null || response.ConversionRates == null || response.Result != "success")
+            {
+                _logger.LogError("汇率API调用失败: {Message}", response?.ErrorType ?? "未知错误");
+                throw new Exception("汇率服务暂时不可用");
+            }
+
+            // 转换为USD -> 目标币种的汇率字典
+            var usdRates = response.ConversionRates;
+
+            // 计算 from -> to 的汇率：(1 from = x USD) * (1 USD = y to) = x*y to
+            decimal fromToUsd = 1 / usdRates[fromCurrency.ToUpper()];
+            decimal usdToTo = usdRates[toCurrency.ToUpper()];
+            decimal rate = fromToUsd * usdToTo;
+
+            // 存入缓存
+            var cacheOptions = new MemoryCacheEntryOptions
+            {
+                AbsoluteExpirationRelativeToNow = TimeSpan.FromHours(CacheExpirationHours)
+            };
+            _cache.Set(cacheKey, rate, cacheOptions);
+
+            // 同时缓存反向汇率
+            string reverseCacheKey = $"{CacheKeyPrefix}{toCurrency}_{fromCurrency}";
+            _cache.Set(reverseCacheKey, 1 / rate, cacheOptions);
+
+            _logger.LogInformation("汇率获取成功: {FromCurrency} -> {ToCurrency} = {Rate}", fromCurrency, toCurrency, rate);
+            return rate;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "获取汇率失败: {FromCurrency} -> {ToCurrency}", fromCurrency, toCurrency);
+            // 失败时降级到Mock汇率
+            return await GetMockFallbackRate(fromCurrency, toCurrency);
+        }
+    }
+
+    public async Task<decimal> ConvertAmountAsync(decimal amount, string fromCurrency, string toCurrency)
+    {
+        _logger.LogInformation("转换金额: {Amount} {FromCurrency} -> {ToCurrency}", amount, fromCurrency, toCurrency);
+
+        if (fromCurrency == toCurrency)
+        {
+            return amount;
+        }
+
+        var rate = await GetExchangeRateAsync(fromCurrency, toCurrency);
+        return amount * rate;
+    }
+
+    /// <summary>
+    /// 失败降级到Mock汇率
+    /// </summary>
+    private Task<decimal> GetMockFallbackRate(string fromCurrency, string toCurrency)
+    {
+        _logger.LogWarning("使用Mock汇率降级: {FromCurrency} -> {ToCurrency}", fromCurrency, toCurrency);
+        
+        var mockRates = new Dictionary<string, decimal>
+        {
+            { "CNY-USD", 0.14m },
+            { "USD-CNY", 7.10m },
+            { "CNY-HKD", 1.09m },
+            { "HKD-CNY", 0.92m },
+            { "USD-HKD", 7.75m },
+            { "HKD-USD", 0.13m }
+        };
+
+        string key = $"{fromCurrency.ToUpper()}-{toCurrency.ToUpper()}";
+        return Task.FromResult(mockRates.TryGetValue(key, out var rate) ? rate : 1.00m);
+    }
+}
+
+/// <summary>
+/// 汇率API响应模型
+/// </summary>
+public class ExchangeRateResponse
+{
+    public string Result { get; set; } = string.Empty;
+    public string ErrorType { get; set; } = string.Empty;
+    public Dictionary<string, decimal> ConversionRates { get; set; } = new();
+}
diff --git a/AssetManager.Infrastructure/Services/IMarketDataService.cs b/AssetManager.Infrastructure/Services/IMarketDataService.cs
index 4681220..7fc2b07 100644
--- a/AssetManager.Infrastructure/Services/IMarketDataService.cs
+++ b/AssetManager.Infrastructure/Services/IMarketDataService.cs
@@ -7,6 +7,24 @@ namespace AssetManager.Infrastructure.Services;
 /// </summary>
 public interface IMarketDataService
 {
+    /// <summary>
+    /// 获取实时价格（自动根据资产类型路由到对应数据源）
+    /// </summary>
+    /// <param name="symbol">标的代码</param>
+    /// <param name="assetType">资产类型（Stock/Crypto）</param>
+    /// <returns>价格信息</returns>
+    Task<MarketPriceResponse> GetPriceAsync(string symbol, string assetType);
+
+    /// <summary>
+    /// 获取历史数据（自动根据资产类型路由到对应数据源）
+    /// </summary>
+    /// <param name="symbol">标的代码</param>
+    /// <param name="assetType">资产类型（Stock/Crypto）</param>
+    /// <param name="timeframe">时间周期</param>
+    /// <param name="limit">数据点数量</param>
+    /// <returns>历史数据列表</returns>
+    Task<List<MarketDataResponse>> GetHistoricalDataAsync(string symbol, string assetType, string timeframe, int limit);
+
     /// <summary>
     /// 获取股票实时价格
     /// </summary>
diff --git a/AssetManager.Infrastructure/Services/MarketDataService.cs b/AssetManager.Infrastructure/Services/MarketDataService.cs
index 7c3eac9..1f72357 100644
--- a/AssetManager.Infrastructure/Services/MarketDataService.cs
+++ b/AssetManager.Infrastructure/Services/MarketDataService.cs
@@ -237,6 +237,43 @@ public class MarketDataService : IMarketDataService
         };
     }
 
+    /// <summary>
+    /// 获取实时价格（自动根据资产类型路由到对应数据源）
+    /// </summary>
+    public async Task<MarketPriceResponse> GetPriceAsync(string symbol, string assetType)
+    {
+        _logger.LogInformation("获取实时价格: {Symbol}, 资产类型: {AssetType}", symbol, assetType);
+        
+        if (assetType.Equals("Crypto", StringComparison.OrdinalIgnoreCase))
+        {
+            return await GetCryptoPriceAsync(symbol);
+        }
+        else
+        {
+            // 默认走股票数据源
+            return await GetStockPriceAsync(symbol);
+        }
+    }
+
+    /// <summary>
+    /// 获取历史数据（自动根据资产类型路由到对应数据源）
+    /// </summary>
+    public async Task<List<MarketDataResponse>> GetHistoricalDataAsync(string symbol, string assetType, string timeframe, int limit)
+    {
+        _logger.LogInformation("获取历史数据: {Symbol}, 资产类型: {AssetType}, 周期: {Timeframe}, 数量: {Limit}", 
+            symbol, assetType, timeframe, limit);
+        
+        if (assetType.Equals("Crypto", StringComparison.OrdinalIgnoreCase))
+        {
+            return await GetCryptoHistoricalDataAsync(symbol, timeframe, limit);
+        }
+        else
+        {
+            // 默认走股票数据源
+            return await GetStockHistoricalDataAsync(symbol, timeframe, limit);
+        }
+    }
+
     /// <summary>
     /// 计算开始日期
     /// </summary>
diff --git a/AssetManager.Services/PortfolioService.cs b/AssetManager.Services/PortfolioService.cs
index a6a3836..5d61388 100644
--- a/AssetManager.Services/PortfolioService.cs
+++ b/AssetManager.Services/PortfolioService.cs
@@ -161,16 +161,8 @@ public class PortfolioService : IPortfolioService
                     continue;
                 }
 
-                // 获取实时价格
-                MarketPriceResponse priceResponse;
-                if (pos.AssetType?.Equals("Crypto", StringComparison.OrdinalIgnoreCase) == true)
-                {
-                    priceResponse = await _marketDataService.GetCryptoPriceAsync(pos.StockCode);
-                }
-                else
-                {
-                    priceResponse = await _marketDataService.GetStockPriceAsync(pos.StockCode);
-                }
+                // 获取实时价格（自动路由数据源）
+                var priceResponse = await _marketDataService.GetPriceAsync(pos.StockCode, pos.AssetType ?? "Stock");
 
                 decimal currentPrice = priceResponse.Price;
                 decimal previousClose = priceResponse.PreviousClose;
@@ -235,16 +227,8 @@ public class PortfolioService : IPortfolioService
                 continue;
             }
 
-            // 获取实时价格
-            MarketPriceResponse priceResponse;
-            if (pos.AssetType?.Equals("Crypto", StringComparison.OrdinalIgnoreCase) == true)
-            {
-                priceResponse = await _marketDataService.GetCryptoPriceAsync(pos.StockCode);
-            }
-            else
-            {
-                priceResponse = await _marketDataService.GetStockPriceAsync(pos.StockCode);
-            }
+            // 获取实时价格（自动路由数据源）
+            var priceResponse = await _marketDataService.GetPriceAsync(pos.StockCode, pos.AssetType ?? "Stock");
 
             decimal currentPrice = priceResponse.Price;
             decimal previousClose = priceResponse.PreviousClose;
@@ -465,16 +449,8 @@ public class PortfolioService : IPortfolioService
                 continue;
             }
 
-            // 获取实时价格
-            MarketPriceResponse priceResponse;
-            if (pos.AssetType?.Equals("Crypto", StringComparison.OrdinalIgnoreCase) == true)
-            {
-                priceResponse = _marketDataService.GetCryptoPriceAsync(pos.StockCode).GetAwaiter().GetResult();
-            }
-            else
-            {
-                priceResponse = _marketDataService.GetStockPriceAsync(pos.StockCode).GetAwaiter().GetResult();
-            }
+            // 获取实时价格（自动路由数据源）
+            var priceResponse = _marketDataService.GetPriceAsync(pos.StockCode, pos.AssetType ?? "Stock").GetAwaiter().GetResult();
 
             decimal currentPrice = priceResponse.Price;
             totalPortfolioValue += pos.Shares * currentPrice;