Abstract: For the high sidelobe of waveforms after pulse compression of the numerical optimization methods in the designing orthogonal waveform for MIMO radar, a method of Golay complementary sequence with space time coding is proposed. The autocorrelation sidelobe and crosscorrelation of the waveform are degraded by utilizing the complementary characteristic of the Golay complementary sequences and extended space time coding the pulse trains of the sequences, as a result, the sidelobe level of the waveform after pulse compression is greatly reduced. Then, to solve the problem of the decrease of target detection ability for Doppler shift, the waveform after pulse compression is Doppler compensated via null space vector weighting method, consequently, the target detection ability of the waveform is significantly improved. The simulation results demonstrate the effectiveness of the method.