diff --git a/server/MiAssessment/src/MiAssessment.Admin/Services/CaptchaService.cs b/server/MiAssessment/src/MiAssessment.Admin/Services/CaptchaService.cs
index c200a01..9969d23 100644
--- a/server/MiAssessment/src/MiAssessment.Admin/Services/CaptchaService.cs
+++ b/server/MiAssessment/src/MiAssessment.Admin/Services/CaptchaService.cs
@@ -178,11 +178,17 @@ public class CaptchaService : ICaptchaService
     /// </summary>
     private void DrawCaptchaText(SKCanvas canvas, string code)
     {
-        using var paint = new SKPaint
+        // 使用默认字体，避免服务器上缺少特定字体导致文字不显示
+        var typeface = SKTypeface.FromFamilyName("Arial", SKFontStyle.Bold)
+                    ?? SKTypeface.FromFamilyName("Microsoft YaHei", SKFontStyle.Bold)
+                    ?? SKTypeface.FromFamilyName(null, SKFontStyle.Bold)
+                    ?? SKTypeface.Default;
+
+        using var font = new SKFont(typeface, 26);
+        using var paint = new SKPaint(font)
         {
             IsAntialias = true,
-            TextSize = 24,
-            Typeface = SKTypeface.FromFamilyName("Arial", SKFontStyle.Bold)
+            Color = SKColors.Black
         };
 
         var charWidth = (ImageWidth - 20) / code.Length;
@@ -192,16 +198,16 @@ public class CaptchaService : ICaptchaService
         {
             // 每个字符使用不同的深色
             paint.Color = new SKColor(
-                (byte)_random.Next(0, 100),
-                (byte)_random.Next(0, 100),
-                (byte)_random.Next(0, 100)
+                (byte)_random.Next(0, 80),
+                (byte)_random.Next(0, 80),
+                (byte)_random.Next(0, 80)
             );
             
             // 随机Y位置（垂直偏移）
-            var y = _random.Next(25, 35);
+            var y = _random.Next(26, 34);
             
             // 绘制字符
-            canvas.DrawText(code[i].ToString(), startX + i * charWidth, y, paint);
+            canvas.DrawText(code[i].ToString(), startX + i * charWidth, y, font, paint);
         }
     }
 }
diff --git a/server/MiAssessment/src/MiAssessment.Api/wwwroot/images/static-pages/01.Jpeg b/server/MiAssessment/src/MiAssessment.Api/wwwroot/images/static-pages/01.Jpeg
index 367a99d..e433d22 100644
Binary files a/server/MiAssessment/src/MiAssessment.Api/wwwroot/images/static-pages/01.Jpeg and b/server/MiAssessment/src/MiAssessment.Api/wwwroot/images/static-pages/01.Jpeg differ