Abstract: Aiming at the project trajectory design problem for target of simple control supersonic rocket target, an optimal guidance law design method of rocket target was proposed base on the particle swarm optimization and Gauss pseudo-spectral method. First, according to the rocket target has the greatest kinetic energy at the beginning of leveled segment, the optimal incident angle and control moment were calculated by using the particle swarm optimization during the climb-leveled segment. Then, the optimal level flight guidance law was calculated based on Gauss pseudo-spectral method. Simulation results show that, using the method proposed, the optimal project trajectory and guidance law can be obtained quickly, as well as the indicators for target can be met well. The method can provide a reference for trajectory design of rocket target.