diff --git a/swift/llm/template/template/seed.py b/swift/llm/template/template/seed.py
index 4392b6c3c9..22dd8ce7ac 100644
--- a/swift/llm/template/template/seed.py
+++ b/swift/llm/template/template/seed.py
@@ -24,9 +24,10 @@ def get_thinking_budget(self, inputs: StdTemplateInputs):
                     if '<think>' in m['content'] and '</think>' in m['content']:
                         _, think = m['content'].split('<think>', maxsplit=1)
                         think, _ = think.split('</think>', maxsplit=1)
-                        thinking_token_len = len(self.tokenizer(think)['input_ids'])
-                        if thinking_token_len > max_length:
-                            max_length = thinking_token_len
+                        if think.strip():
+                            thinking_token_len = len(self.tokenizer(think)['input_ids'])
+                            if thinking_token_len > max_length:
+                                max_length = thinking_token_len
 
         def convert_integer_v2(n):
             if n is None: