diff --git a/Katheryne/KatheryneChatRobot.cs b/Katheryne/KatheryneChatRobot.cs
index c84e5f3..644f8f5 100644
--- a/Katheryne/KatheryneChatRobot.cs
+++ b/Katheryne/KatheryneChatRobot.cs
@@ -1,8 +1,7 @@
+using System.Text.RegularExpressions;
 using Katheryne.Abstractions;
 using Katheryne.Models;
-using Katheryne.Services;
 using Microsoft.Extensions.Logging;
-using YamlDotNet.Serialization;
 
 namespace Katheryne;
 
@@ -28,7 +27,7 @@ public class KatheryneChatRobot : IChatRobot
     {
         return new[]
         {
-            _grammarTree[_currentStage]
+            _grammarTree[_currentStage].Answer
         };
     }
 
@@ -42,13 +41,51 @@ public class KatheryneChatRobot : IChatRobot
 
     public IEnumerable<string> ChatNext(string input)
     {
-        _logger.LogDebug("Receive input {} on stage {}.", input, _currentStage);
-        (_currentStage, string answer) = _grammarTree.NextStage(_currentStage, input);
-        _logger.LogDebug("Change stage to {}.", _currentStage);
+        List<string> result = new();
 
-        return new[]
+        foreach (InnerTransformer transformer in _grammarTree[_currentStage].Transformers)
         {
-            answer
-        };
+            if (transformer.Pattern is null)
+            {
+                continue;
+            }
+            
+            Match match = transformer.Pattern.Match(input);
+
+            if (match.Success)
+            {
+                _currentStage = transformer.NextStage;
+                result.Add(_grammarTree[_currentStage].Answer);
+                _logger.LogDebug("Moving to stage {}.", _currentStage);
+            }
+        }
+        
+        EmptyTransform(result);
+        return result;
+    }
+
+    /// <summary>
+    /// 进行当前阶段的空转移
+    /// </summary>
+    /// <param name="result">存放输出回答的列表</param>
+    private void EmptyTransform(List<string> result)
+    {
+        var flag = true;
+        while (flag)
+        {
+            flag = false;
+            foreach (InnerTransformer transformer in _grammarTree[_currentStage].Transformers)
+            {
+                if (string.IsNullOrEmpty(transformer.RowPattern))
+                {
+                    flag = true;
+                    _currentStage = transformer.NextStage;
+                    result.Add(_grammarTree[_currentStage].Answer);
+                    
+                    _logger.LogDebug("Moving to stage {} with empty transform.", _currentStage);
+                    break;
+                }
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/Katheryne/Models/GrammarTree.cs b/Katheryne/Models/GrammarTree.cs
index c76d694..2c4effa 100644
--- a/Katheryne/Models/GrammarTree.cs
+++ b/Katheryne/Models/GrammarTree.cs
@@ -1,4 +1,3 @@
-using System.Text.RegularExpressions;
 using Katheryne.Exceptions;
 
 namespace Katheryne.Models;
@@ -19,33 +18,9 @@ public class GrammarTree
             throw new GrammarException("使用了未声明的阶段名");
         }
     }
+    
 
-    /// <summary>
-    /// 获得下一个阶段
-    /// </summary>
-    /// <param name="currentStage">当前所在阶段</param>
-    /// <param name="input">用户输入</param>
-    /// <returns>元组，第一个参数是下一个阶段名称 第二个参数是机器人回答</returns>
-    /// <exception cref="GrammarException"></exception>
-    public (string, string) NextStage(string currentStage, string input)
-    {
-        List<InnerTransformer> transformers = _stages[currentStage].Transformers;
-
-        foreach (InnerTransformer transformer in transformers)
-        {
-            Match match = transformer.Pattern.Match(input);
-
-            if (match.Success)
-            {
-                return (_stages[transformer.NextStage].Name,
-                    _stages[transformer.NextStage].Answer);
-            }
-        }
-
-        throw new GrammarException("Failed to get next stage.");
-    }
-
-    public string this[string index] => _stages[index].Answer;
+    internal InnerStage this[string index] => _stages[index];
 
     /// <summary>
     /// 主要验证语法的两个特点
@@ -65,45 +40,4 @@ public class GrammarTree
             return stage.Transformers.All(t => _stages.ContainsKey(t.NextStageName));
         });
     }
-    
-    private class InnerStage
-    {
-        public string Name { get; }
-
-        public List<InnerTransformer> Transformers { get; } = new();
-        
-        public string Answer { get; }
-
-        public InnerStage(Stage stage)
-        {
-            Name = stage.Name;
-            Answer = stage.Answer;
-
-            foreach (Transformer transformer in stage.Transformers)
-            {
-                Transformers.Add(new InnerTransformer(transformer));
-            }
-        }
-    }
-    
-    private class InnerTransformer
-    {
-        public Regex Pattern { get; }
-        
-        public string NextStage { get; }
-
-        public InnerTransformer(Transformer transformer)
-        {
-            NextStage = transformer.NextStageName;
-
-            try
-            {
-                Pattern = new Regex(transformer.Pattern);
-            }
-            catch (ArgumentException e)
-            {
-                throw new GrammarException($"Failed to Parse regex:{transformer.Pattern}.", e);
-            }
-        }
-    }
 }
\ No newline at end of file
diff --git a/Katheryne/Models/InnerStage.cs b/Katheryne/Models/InnerStage.cs
new file mode 100644
index 0000000..29aec60
--- /dev/null
+++ b/Katheryne/Models/InnerStage.cs
@@ -0,0 +1,21 @@
+namespace Katheryne.Models;
+
+internal class InnerStage
+{
+    public string Name { get; }
+
+    public List<InnerTransformer> Transformers { get; } = new();
+        
+    public string Answer { get; }
+
+    public InnerStage(Stage stage)
+    {
+        Name = stage.Name;
+        Answer = stage.Answer;
+
+        foreach (Transformer transformer in stage.Transformers)
+        {
+            Transformers.Add(new InnerTransformer(transformer));
+        }
+    }
+}
\ No newline at end of file
diff --git a/Katheryne/Models/InnerTransformer.cs b/Katheryne/Models/InnerTransformer.cs
new file mode 100644
index 0000000..b306103
--- /dev/null
+++ b/Katheryne/Models/InnerTransformer.cs
@@ -0,0 +1,33 @@
+using System.Text.RegularExpressions;
+using Katheryne.Exceptions;
+
+namespace Katheryne.Models;
+
+internal class InnerTransformer
+{
+    public Regex? Pattern { get; }
+        
+    public string RowPattern { get; }
+        
+    public string NextStage { get; }
+
+    public InnerTransformer(Transformer transformer)
+    {
+        NextStage = transformer.NextStageName;
+        RowPattern = transformer.Pattern;
+
+        if (string.IsNullOrEmpty(RowPattern))
+        {
+            return;
+        }
+
+        try
+        {
+            Pattern = new Regex(transformer.Pattern);
+        }
+        catch (ArgumentException e)
+        {
+            throw new GrammarException($"Failed to Parse regex:{transformer.Pattern}.", e);
+        }
+    }
+}
\ No newline at end of file