The existence of clearance causes the contact-impact of joint elements,which would change the dynamic characteristics of mechanical systems.The dynamic model of high-speed and ultra-precision press system with multiple clearance joints was established,considering the nonlinear contact characteristics.The L-N contact model and Coulomb model were introduced in the dynamic equations of mechanical systems.The dynamic behavior of high-speed and ultra-precision mechanism was conducted by the Runge-Kutta scheme.The simulation results were compared with the experiment data,which demonstrated the correctness and effectiveness of the proposed method.Moreover,the effects of rotational speed and clearance size on the dynamic behavior of high-speed and ultra-precision mechanism were conducted.The results reveal that the different motion states of joint elements appear,〖JP2〗which causes a greater impact and collision.The various of rotational speed and clearance size causes the non-periodic dynamic response of high-〖JP〗speed and ultra-precision mechanism and chaotic phenomenon.