The Magnus effect heavily affects the flight stability and trajectory calculation of the spinning projectile. A simple method based on rotating wall technique to calculate the effect of a rotating projectile with several planes of symmetry has been developed. Instead of using the dynamic mesh or multi-reference frame model, this method adds the rotating velocity to the surface of the projectile, and the Magnus force and moment can be obtained with steady calculations. The SOCBT configuration is used to testify the method. The calculation results are consistent with the experimental data in both static and rotating cases. Moreover, as the interference among the boundary layer, the separation flow at high angle of attack and the shock wave, enough gird nodes in boundary layer, as well as the calculating models, are needed to improve the precision of the Magnus effect simulation.