The virtual axis hybrid polishing machine tool (VAHMPT) is the novel equipment developed by the authors that is aimed at the precision machining on the free-form curved surfaces. This paper establishes the dynamic equations of the spatial rigid-flexible coupling multibody systems considering the coupling for the rigid movement of the whole VAHMPT with the elastic deformation of each leg by means of the theory of dynamics of flexible multibodysystems. Meanwhile the dynamic characteristics of the hybrid machine tool is studied in detail by the dynamics simulation analysis. The dynamic simulation of the machine shows that the elastic deformation of each leg is very small during the movement of the machine and the influence of the flexibility of each leg on the trace of moving platform is not obvious due to the characteristics of joints. The dynamic characteristics of the VAHPMT is verified combining with the experiments. It is shown that the experiments result is almost accorded with the simulation analysis. The satisfied polishing effect on the curved surfaces can be obtained and the demand of the polishing can be achieved by the VAHPMT.