The present invention discloses a method for determining user channel impulse response in the TD-SCDMA system, including: setting one or more than one synchronous ID code and establishing corresponding relations between channel estimation parameters of each user and the synchronous ID code and a sub-frame number of a sub-frame transmitting the synchronous ID code; transmitting, by each user, a corresponding synchronous ID code in a sub-frame identified by a sub-frame number corresponding to channel estimation parameters according to the relations established in step A, wherein timing advance of transmitting the synchronous ID code is the same with that of transmitting uplink service data of the user; at Node B, continuing to detect whether there is the synchronous ID code in received signals, if there is one or more than one synchronous ID code, determining the channel estimation parameters of the user transmitting the synchronous ID code according to the detected synchronous ID code, sub-frame number of the current sub-frame and the corresponding relations established in step A; and at Node B, computing the channel impulse response of the user according to the determined channel estimation parameters and arriving time of the detected synchronous ID code.