Applicability of numerical prediction method of dynamic derivatives is studied with forced oscillation method and free oscillation method on the airframe/propulsion integrative vehicle with and without fairing. Effect of parameters on dynamic derivative prediction in forced oscillation method such as time step and oscillation frequency is analyzed in detail. It shows that forced oscillation method is well applied in dynamic derivative prediction of integrative vehicle with internal and external flow, while parameters select of time step, computational time and oscillation frequency are quite different from external-flow-only vehicle. Dynamic derivatives by free oscillation method are in agreement with results with forced oscillation method on external-flow-only vehicle. There is a difference about 50% on integrative vehicle with internal and external flow. Origin and mechanism of differences in two methods need to be deeply studied.