In order to improve dynamic characteristics of high-speed spatial PCMM (parallel coordinate measuring machine), the virtual prototype technology was applied to the elastodynamics optimization design of PCMM. Integrating CAD, CAE and visual technologies, the rigid-flexible virtual prototyping of PCMM was built. The influence law of the mass of moving platform and the diameter of driving limbs on the dynamic behaviors, including kinematics output response and maximum dynamic stress of driving limbs were discussed. On these grounds, the mass of moving platform and the diameter of driving limbs were optimized. The optimal results, which include the mass of moving platform of 80.85kg and the diameter of driving limbs of 44mm, were obtained. The simulation results showed the maximum dynamic stress of driving limbs were decreased to 17.5MPa, the kinematics output response were also reduced, so that the obvious improvement of the dynamics characteristics for PCMM was realized, and the powerful theoretical basis and method were provided.