Savitzky Golay (SG) filtering algorithm is an effective algorithm to remove the white noise in digital signal. The algorithm is based on the least squares algorithm, whose essential concern is how to ensure the filtering effect while remain the information of signals as much as possible. A SG threshold value filtering algorithm is put forward through the theoretical analysis to take different SG filtering strategy in different signal intervals with different characteristics. Then, based on the white noise singular point detection and iterative algorithm, a threshold value determination algorithm is proposed to enhance the practicability and the convenience of the SG threshold value filtering algorithm.