The pump performance is directly affected by the dynamics performance of pistonslipper group. Since the timevarying direction and magnitude of centrifugal force of pistonslipper group, friction force of slipper swash plate pair, and the interaction force between piston and bush, etc., the conventional dynamics parameters analysis of pistonslipper group is merely limited to either at a certain fixed position or with some simplification assumptions, which are unbeneficial to the optimization design of pump and the prospective evaluation of pump performance. In order to dynamically evaluate the dynamics performance of pistonslipper group over the whole operating period, a novel simplified mathematic model neglecting the action of centrifugal force of pistonslipper group and friction force of slipper swash plate pair, and a novel elaborated mathematic model considering the effect of all the forces acting on the pistonslipper group were put forward, which both accord with the actual condition of line contact force between piston and cylinder bore, and further take the continuous variation of force acting position between piston and cylinder bore with the change of working conditions of pump into account. The novel mathematic models were verified by the experimental results and the simulated results by distribution parameter method based on commercial softwares. The application practice indicates that the proposed models can be used to dynamically evaluate the dynamics parameters of pistonslipper group over the whole operating period, and serve the dynamic optimization design of pump.