diff --git a/yuthon_official/models/yuthon_official.py b/yuthon_official/models/yuthon_official.py
index 4703ed1d3..86c3e940c 100644
--- a/yuthon_official/models/yuthon_official.py
+++ b/yuthon_official/models/yuthon_official.py
@@ -197,28 +197,23 @@ class YuthonOfficial(models.Model):
             prefix = prefix_map.get(company_name)
             if not prefix:
                 return
+
             year_str = f"〔{current_year}〕"
             domain = [
                 ('company_id1', '=', self.company_id1.id),
                 ('reference_cold', 'like', f"{prefix}{year_str}%")
             ]
             last_record = self.search(domain, order='reference_cold desc', limit=1)
+            base_num = 27 if (current_year == 2026 and company_name == "集团本部") else 1
+            max_seq = 0
             if last_record and last_record.reference_cold:
                 try:
                     seq_str = last_record.reference_cold.split(year_str)[1].rsplit('号', 1)[0]
-                    last_seq = int(seq_str)
-                    next_seq = last_seq + 1
-                except (IndexError, ValueError):
-                    if current_year == 2026 and company_name == '集团本部':
-                        next_seq = 27
-                    else:
-                        next_seq = 1
-            else:
-                if current_year == 2026 and company_name == '集团本部':
-                    next_seq = 27
-                else:
-                    next_seq = 1
+                    max_seq = int(seq_str)
+                except:
+                    max_seq = 0
 
+            next_seq = max(max_seq + 1, base_num)
             self.reference_cold = f"{prefix}{year_str}{next_seq}号"
 
     def supervising_button(self):