In order to optimize the dynamic design parameters of 6_PUS parallel mechanism for wind tunnel support system,based on influence coefficient and Lagrange dynamics method, dynamics equation of a kind of 6_PUS parallel robot was built. Based on ARMSTRONG friction model, the dynamic characteristics of this high-dissipation parallel mechanism were analyzed. It is found that the friction power consumption is the most main part of the mechanism power by simulation,and its force has the character of peak,the speed and acceleration of its' sliders have symmetry. These simulation results are useful to the design of this parallel support robot.