By analysis and study of various kinds of flow distribution disks, a new type of distribution disk with double V-shaped unloading slots is designed with optimization again.The new designed disk was loaded into the piston pump by Computational Flow Dynamics (CFD) software to simulate.Through simulation, it is concluded that the width of the triangle slot of the distribution disk is about 10°, the slope angle is about 12°, and the diameter of the unloading hole is about 08 mm. When the diameter of the perforated hole is about 15 mm, the flow curve of the unloading hole is the smoothest. Pressure shock and noise are also minimized at this time.The results show that by improving the damping tank, the flow noise and cavitation change are both smaller than before.