Abstract: An approach is proposed coordinately to model and simulate the dynamics of flexible multibody of a mechanism, and a spatial dynamic equation is given to the flexible mechanism on the basis of the dynamics of multibody system. Then, a simulation model is developed for the dynamics of flexible multibody of 3-TPT parallel robots by use of the software ADAMS for multibody dynamics and ANSYS for FEA, and the model is studied dynamically by simulation. To discuss the results more exactly, the simulation results of rigid and flexible bodies are compared with each other. Simulation results showed that the forces acting on any flexible members are highly nonlinear, and the judgment conforms to the actuality. Such simulation results will reflect dynamically and actually how the parallel robots operate more really and exactly, as well as the prediction of the performance of a mechanism. The approach proposed will provide a method to analyze the design and optimization of parallel robots.