A parallel platform mechanism is put forward, in which the number of inputs is six and the DOF (degree of freedom) of moving platform is three. The inputs of the mechanism are redundant for the moving platform. The DOF of the system is six as the coordination components are incorporated, and the inputs are determinate for the whole mechanism. So the problem of distribution of over-determinate inputs is avoided and the mechanism has advantages like redundant actuation mechanism. The generalized outputs of mechanism are the movements of moving platform and coordination components. By analyzing kinematics of the mechanism, the mapping relationship between inputs and generalized outputs is established, and the first-order and second-order influence coefficient matrix are obtained respectively. Based on the virtual work principle and D'Alembert principle, the dynamic model of the mechanism is built. The simulation results show that the parallel platform mechanism has the characteristics of high load carrying capacity. The method proposed is a new solution to design parallel mechanisms with heavy load carrying capability.