diff --git a/Controllers/SimApiBaseController.cs b/Controllers/SimApiBaseController.cs
index b9a35e2..00c7001 100644
--- a/Controllers/SimApiBaseController.cs
+++ b/Controllers/SimApiBaseController.cs
@@ -55,7 +55,7 @@ public class SimApiBaseController : Controller
     /// <param name="condition">检测条件</param>
     /// <param name="code">错误代码</param>
     /// <param name="message">错误描述</param>
-    protected static void ErrorWhen(bool condition, int code = 500, string message = "")
+    protected static void ErrorWhen(bool condition, int code = 400, string message = "")
     {
         if (condition)
         {
@@ -70,7 +70,7 @@ public class SimApiBaseController : Controller
     /// <param name="condition">检测条件</param>
     /// <param name="code">错误代码</param>
     /// <param name="message">错误描述</param>
-    protected static void ErrorWhenTrue(bool condition, int code = 500, string message = "")
+    protected static void ErrorWhenTrue(bool condition, int code = 400, string message = "")
     {
         ErrorWhen(condition, code, message);
     }
@@ -82,7 +82,7 @@ public class SimApiBaseController : Controller
     /// <param name="condition"></param>
     /// <param name="code"></param>
     /// <param name="message"></param>
-    protected static void ErrorWhenFalse(bool condition, int code = 500, string message = "")
+    protected static void ErrorWhenFalse(bool condition, int code = 400, string message = "")
     {
         ErrorWhen(!condition, code, message);
     }
@@ -93,7 +93,7 @@ public class SimApiBaseController : Controller
     /// <param name="condition">检测条件</param>
     /// <param name="code">错误代码</param>
     /// <param name="message">错误描述</param>
-    protected static void ErrorWhenNull(object condition, int code = 404, string message = "")
+    protected static void ErrorWhenNull(object condition, int code = 404, string message = "请求的资源不存在")
     {
         ErrorWhen(condition == null, code, message);
     }
diff --git a/Helpers/SimApiUtil.cs b/Helpers/SimApiUtil.cs
index c659380..e1bdbae 100644
--- a/Helpers/SimApiUtil.cs
+++ b/Helpers/SimApiUtil.cs
@@ -51,16 +51,15 @@ public static class SimApiUtil
     /// <returns></returns>
     public static string Md5(string source, string mode = "x2")
     {
-        var sor = Encoding.UTF8.GetBytes(source);
-        var md5 = MD5.Create();
-        var result = md5.ComputeHash(sor);
-        var strbul = new StringBuilder(40);
+        var sourceBytes = Encoding.UTF8.GetBytes(source);
+        var result = MD5.HashData(sourceBytes);
+        var stringBuilder = new StringBuilder(40);
         foreach (var t in result)
         {
-            strbul.Append(t.ToString(mode));
+            stringBuilder.Append(t.ToString(mode));
         }
 
-        return strbul.ToString();
+        return stringBuilder.ToString();
     }
 
     /// <summary>
diff --git a/Middlewares/SimApiExceptionMiddleware.cs b/Middlewares/SimApiExceptionMiddleware.cs
index 10b3cb6..30099f4 100644
--- a/Middlewares/SimApiExceptionMiddleware.cs
+++ b/Middlewares/SimApiExceptionMiddleware.cs
@@ -24,12 +24,17 @@ public class SimApiExceptionMiddleware(RequestDelegate next, ILogger<SimApiExcep
         try
         {
             await next(context);
-            if (context.Response.StatusCode != 200)
+            switch (context.Response.StatusCode)
             {
-                if (!new[] { 301, 302 }.Contains(context.Response.StatusCode))
-                {
+                case 200:
+                    break;
+                case 404:
+                    throw new SimApiException(context.Response.StatusCode, "请求的接口不存在");
+                case 301:
+                case 302:
+                    break;
+                default:
                     throw new SimApiException(context.Response.StatusCode);
-                }
             }
         }
         catch (SimApiException ex)
@@ -42,8 +47,8 @@ public class SimApiExceptionMiddleware(RequestDelegate next, ILogger<SimApiExcep
         }
         catch (Exception ex)
         {
-            log.LogError(ex.Message);
-            log.LogError(ex.StackTrace);
+            log.LogError("{Msg}", ex.Message);
+            log.LogError("{Msg}", ex.StackTrace);
             response = new SimApiBaseResponse(500, ex.Message);
             ErrorResponse(context, response);
         }
@@ -54,13 +59,11 @@ public class SimApiExceptionMiddleware(RequestDelegate next, ILogger<SimApiExcep
     /// </summary>
     /// <param name="context"></param>
     /// <param name="response"></param>
-    private void ErrorResponse(HttpContext context, SimApiBaseResponse response)
+    private static void ErrorResponse(HttpContext context, SimApiBaseResponse response)
     {
-        if (!context.Response.HasStarted)
-        {
-            context.Response.StatusCode = 200;
-            context.Response.Headers.Append("Content-Type", "application/json");
-            context.Response.WriteAsync(response.ToString());
-        }
+        if (context.Response.HasStarted) return;
+        context.Response.StatusCode = 200;
+        context.Response.Headers.Append("Content-Type", "application/json");
+        context.Response.WriteAsync(response.ToString());
     }
 }
\ No newline at end of file