An algorithm for identification of linear time-invariant system impulse response was studied by using m-sequence under the condition of multiple sampling within one clock cycle series. An expression described impulse response sequence with the m-sequences' cycle, amplitude and the sampling rate was derived. For this purpose, the bipolar m-sequence signal autocorrelation property was sampled uniformly, and the unified expression in whole cycle was given and was introduced into Wiener-Hopf calculation to obtain the system's impulse response. Then, the system's impulse response was expressed as the sequences of the input signal and output signal with the cyclic shift matrix. Simulation on the MATLAB platform proved the correctness of the algorithm.