A three-dimensional model of 2-DOF vibration screen was established and the working principle of this vibration screen was analyzed.The model was simplified and the motion parameters were analyzed through analyzing the displacement,velocity,acceleration and the force to improve the efficiency of the screen.The rationality of the design of 2-DOF vibration screen was confirmed.A model of 1-DOF vibration screen and 2-DOF vibration screen were established with ADAMS simulation software to verify how the output freedom affects the movement of the screen.The curves of screen surface inclination,horizontal displacement and acceleration,vertical displacement and acceleration from two different screens were obtained through simulation analysis.The horizontal acceleration of 2-DOF vibration screen was larger than that of 1-DOF.The vertical acceleration of 2-DOF vibration screen was less than that of 1-DOF.It is indicated that this design requirements is reasonable.It will provide a reference for optimizing the vibration screen.