diff --git a/paddlespeech/t2s/frontend/tone_sandhi.py b/paddlespeech/t2s/frontend/tone_sandhi.py
index 690f69aa2..ad3b29714 100644
--- a/paddlespeech/t2s/frontend/tone_sandhi.py
+++ b/paddlespeech/t2s/frontend/tone_sandhi.py
@@ -237,31 +237,26 @@ class ToneSandhi():
     # output seg: [['听一听', 'v']]
     def _merge_yi(self, seg: List[Tuple[str, str]]) -> List[Tuple[str, str]]:
         new_seg = []
-        # function 1
-        for i, (word, pos) in enumerate(seg):
-            if i - 1 >= 0 and word == "一" and i + 1 < len(seg) and seg[i - 1][
-                    0] == seg[i + 1][0] and seg[i - 1][1] == "v":
-                if i - 1 < len(new_seg):
-                    new_seg[i -
-                            1][0] = new_seg[i - 1][0] + "一" + new_seg[i - 1][0]
-                else:
-                    new_seg.append([word, pos])
-                    new_seg.append([seg[i + 1][0], pos])
-            else:
-                if i - 2 >= 0 and seg[i - 1][0] == "一" and seg[i - 2][
-                        0] == word and pos == "v":
-                    continue
-                else:
-                    new_seg.append([word, pos])
-        seg = new_seg
-        new_seg = []
-        # function 2
-        for i, (word, pos) in enumerate(seg):
-            if new_seg and new_seg[-1][0] == "一":
-                new_seg[-1][0] = new_seg[-1][0] + word
-            else:
-                new_seg.append([word, pos])
-        return new_seg
+    skip_next = False
+    # function 1
+    for i, (word, pos) in enumerate(seg):
+        if skip_next:
+            skip_next = False
+            continue
+        if i - 1 >= 0 and word == "一" and i + 1 < len(seg) and seg[i - 1][0] == seg[i + 1][0] and seg[i - 1][1] == "v":
+            new_seg[-1] = (new_seg[-1][0] + "一" + seg[i + 1][0], new_seg[-1][1])
+            skip_next = True
+        else:
+            new_seg.append((word, pos))
+    seg = new_seg
+    new_seg = []
+    # function 2
+    for i, (word, pos) in enumerate(seg):
+        if new_seg and new_seg[-1][0] == "一":
+            new_seg[-1] = (new_seg[-1][0] + word, new_seg[-1][1])
+        else:
+            new_seg.append((word, pos))
+    return new_seg
 
     # the first and the second words are all_tone_three
     def _merge_continuous_three_tones(