Abstract: The rigid body dynamics model of the 6-PUS parallel mechanism is presented based on Newton-Euler method. In order to contain the effect of the gravity and inertia force of all components, a series of coordinates on components are established with D-H method. As a result, closed-form equations for the inverse kinematics of a single chain are derived, and mapping relationships of velocity and acceleration between the mobile platform and the components are given. Then the dynamics model of 6-PUS parallel mechanism is deduced based on the platform, as an example, the driving force curves for circumferential translation are presented. This paper establishes the basis for dynamics analysis of mechanism of this type.