Abstract: Orthogonal signal waveform design is a research hotspot in the field of MIMO radar. With the development of technology, the performance requirement of MIMO radar on orthogonal signal waveform is becoming higher. At present, the orthogonal signal of MIMO radar has the problem of high waveform cross-correlation peak and slow convergence speed. In order to improve the performance of long orthogonal signal waveform, quantum genetic algorithm (QGA) was used in this paper to combine quantum computation and genetic algorithm to reduce the cross correlation peak of waveform. We reduced the mutual interference between different target echoes and improved the detection performance of radar system. Furthermore, we made it more difficult for the enemy to locate the radar systems, and improved the battlefield survivability of the radar. Simulation results show that this method can effectively improve the orthogonal performance of waveforms and speed up the optimization speed.