By using analysis software ADAMS, a parameterized model of equipment in parallel motion simulation platform was established, and verified through simulation test. Aiming at the model, the kinematic analysis and dynamics analysis of the platform were carried. The key control parameters of the platform structure were chosen as design variables, and the sensitivity of design variables was analyzed. On the basis of it, optimization design was carried out on the platform mechanism by selecting the overall performance and loading of hydraulic cylinder as target function, optimal platform structure is achieved.