diff --git a/RespCoarseAlign.py b/RespCoarseAlign.py
index facec96..cda2541 100644
--- a/RespCoarseAlign.py
+++ b/RespCoarseAlign.py
@@ -231,7 +231,7 @@ class Data:
             low = lowCut / (fs * 0.5)
             high = highCut / (fs * 0.5)
             sos = signal.butter(order, [low, high], btype="bandpass", output='sos')
-            return signal.sosfilt(sos, data)
+            return signal.sosfiltfilt(sos, data)
 
         # 滤波
         self.processed_THO = butter_bandpass_filter(self.raw_THO, self.Config["RespFilterConfig"]["LowCut"],