The model of inverse kinematics of six DOF (degree of freedom) 6-3-3 parallel mechanism was established in this paper. The dynamic equations of this parallel mechanism were derived from Newton-Euler approach of rigid-body dynamics, and the matrix QR decomposition method for solving the dynamic equations was presented. Then, the inverse dynamic behavior of this parallel mechanism was simulated by computer software. Finally, validity of this dynamic model was verified by simulation and comparison of two examples. The results showed that dynamic behavior of the parallel mechanism is practicable and can expedite the design process.