This paper deals with the design and dynamic control simulation of a new type of 4-DOF parallel mechanism providing 3 translations and 1 rotation for high-speed handling and machining. This parallel mechanism is named as H4. A model-based dynamic control scheme is developed to improve the accuracy of the trajectory tracking. A simplified dynamic model is used for the H4 robot to decrease the cost of computation. A dynamic simulation is performed using ADAMSTM. The Adept motion is used as a benchmark test to evaluate the effect of the dynamic control. The simulation results show that the proposed dynamic control dramatically improves the trajectory tracking accuracy.