diff --git a/App.xaml.cs b/App.xaml.cs
index 499da10..0770562 100644
--- a/App.xaml.cs
+++ b/App.xaml.cs
@@ -1,6 +1,7 @@
 using System.Configuration;
 using System.Data;
 using System.Diagnostics;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -333,11 +334,19 @@ namespace DrillTools
                 if (selectionWindow.SelectedFilePath == null)
                     return;
 
-                RouParameterReplacer.ReplaceParameters(filePath, selectionWindow.SelectedFilePath);
+                RouParameterReplacer.ReplaceParameters(filePath, selectionWindow.SelectedFilePath, out var unmatchedDiameters);
+
+                string message = $"参数替换完成：\n{filePath}\n原文件已备份为：\n{Path.GetFileName(filePath)}.bak";
+
+                if (unmatchedDiameters.Count > 0)
+                {
+                    var diaStrings = unmatchedDiameters.Select(d => d.ToString("F3", CultureInfo.InvariantCulture)).ToList();
+                    message += $"\n\n⚠ 以下直径未找到匹配参数，已保留原行：\n{string.Join(", ", diaStrings)}";
+                }
 
                 System.Windows.MessageBox.Show(
-                    $"参数替换完成：\n{filePath}\n原文件已备份为 .bak",
-                    "替换完成",
+                    message,
+                    "参数替换完成",
                     MessageBoxButton.OK,
                     MessageBoxImage.Information);
             }
diff --git a/RouParameterReplacer.cs b/RouParameterReplacer.cs
index 7639afc..d279ada 100644
--- a/RouParameterReplacer.cs
+++ b/RouParameterReplacer.cs
@@ -36,7 +36,7 @@ namespace DrillTools
         /// </summary>
         /// <param name="rouFilePath">.rou 文件完整路径</param>
         /// <param name="paramFilePath">参数 .txt 文件完整路径</param>
-        public static void ReplaceParameters(string rouFilePath, string paramFilePath)
+        public static void ReplaceParameters(string rouFilePath, string paramFilePath, out List<double> unmatchedDiameters)
         {
             // 1. 读取参数文件，构建直径→参数字符串映射
             var paramDict = LoadParameterDictionary(paramFilePath);
@@ -47,8 +47,9 @@ namespace DrillTools
             // 2. 读取 .rou 文件
             string rouContent = CommandTypeFileReader.ReadAllText(rouFilePath);
 
-            // 3. 执行替换
-            string replacedContent = ReplaceParametersInContent(rouContent, paramDict);
+            // 3. 执行替换（同时收集未匹配直径）
+            var unmatchedSet = new HashSet<double>();
+            string replacedContent = ReplaceParametersInContent(rouContent, paramDict, unmatchedSet);
 
             // 4. 备份原文件
             string backupFilePath = rouFilePath + ".bak";
@@ -57,6 +58,9 @@ namespace DrillTools
             // 5. 写回文件
             using var writer = new StreamWriter(rouFilePath, false, Encoding.GetEncoding(Gb2312CodePage));
             writer.Write(replacedContent);
+
+            // 6. 输出未匹配直径
+            unmatchedDiameters = new List<double>(unmatchedSet);
         }
 
         /// <summary>
@@ -92,7 +96,7 @@ namespace DrillTools
         /// <summary>
         /// 在 .rou 文件内容中，将 M48～% 区域内的刀径行末尾追加参数。
         /// </summary>
-        private static string ReplaceParametersInContent(string rouContent, Dictionary<double, string> paramDict)
+        private static string ReplaceParametersInContent(string rouContent, Dictionary<double, string> paramDict, HashSet<double> unmatchedDiameters)
         {
             var lines = DrillTapeLineParser.SplitLines(rouContent);
             var builder = new StringBuilder(rouContent.Length + 1024);
@@ -144,6 +148,10 @@ namespace DrillTools
                             builder.Append(line.LineEnding);
                             continue;
                         }
+                        else
+                        {
+                            unmatchedDiameters.Add(diameter);
+                        }
                     }
                 }