diff --git a/AssetManager.Services/PortfolioService.cs b/AssetManager.Services/PortfolioService.cs
index f293bbc..9c8f6a7 100644
--- a/AssetManager.Services/PortfolioService.cs
+++ b/AssetManager.Services/PortfolioService.cs
@@ -359,6 +359,26 @@ public class PortfolioService : IPortfolioService
             throw new Exception("Portfolio not found or access denied");
         }
 
+        // 卖出操作校验
+        if (request.type?.ToLower() == "sell")
+        {
+            // 校验是否有该持仓
+            var position = _db.Queryable<Position>()
+                .Where(pos => pos.PortfolioId == request.portfolioId && pos.StockCode == request.stockCode)
+                .First();
+
+            if (position == null)
+            {
+                throw new Exception($"该组合中不存在标的 {request.stockCode}，无法卖出");
+            }
+
+            // 校验卖出数量不超过持仓数量
+            if (request.amount > (double)position.Shares)
+            {
+                throw new Exception($"卖出数量不能超过持仓数量，当前持仓 {position.Shares} 份");
+            }
+        }
+
         // 解析实际交易时间，如果解析失败则用当前时间
         DateTime transactionTime = DateTime.Now;
         if (!string.IsNullOrEmpty(request.transactionDate))