To study the effects of initial disturbance on an inclined vehicle launcher at launch, a rigidflexible coupling model is established by using ADAMS and ANSYS. The disturbance factors such as thrust eccentricity and locking force are simulated and analyzed. The results show that the thrust misalignment of the engine is a disturbance factor that cannot be neglected and the load deformation capacity of the missile back component should be strengthened. Through comparison and analysis, it is concluded that the locking force should be reduced as much as possible under the premise of meeting the design requirements.