In order to solve the dynamic and kinematic tight coupled problem existed during missile separating from cavity and in order to acquire accurate trajectory parameters for control system a parallel collaborative simulation platform was established based on Fluent and Simulink.The Journal file of Fluent and S-function of Simulink were adopted and the data interface between Fluent and Simulink was developed by sharing data file.The missile′s rudder control model was established.The aerodynamic characteristics and trajectory characteristics during missile separating from cavity were simulated under uncontrolled and closed-loop controlled conditions.The simulation results verify the feasibility of parallel collaborative simulation and show that rudder control method can effectively improve the ballistic trajectory characteristics when missile separating from cavity.