Abstract: Conventional control law validation method based on modeling and simulation is highly relevant with model quality and is difficult to obtain correct results when dynamic effect is strong. An attempt is made to use CFD based virtual flight simulation to validate and optimize control laws. The numeric method is introduced and validated through open-loop longitudinal virtual flight which has a good agreement with experiment and computer simulation results. Then a PID controller is designed for the pitch-up motion which has good dynamic performance for step response simulation. However, CFD simulation result shows that its overshoot exceeds 50% and setting time is 1.7s. Finally the controller is optimized through CFD simulation by using different parameters. The final controller has a much smaller overshoot and setting time which are 14% and 1.18s respectively. Analysis shows that the control fin deflection rate is 200?s, resulting in strong dynamic effect which cannot be depicted by the aerodynamic model and induces the significant difference of computer simulation. Simulation results show that virtual flight simulation can play a key role in the analysis of control method.