With the dual axial piston pump as the research object, according to the characteristics of new double plunger pump flow distribution disk, in order to adapte to working condition, the form of disk was selected. The design size was deduced of the angle of transition zone of disk, trangle damping groove and damping hole. The simulation analysis was carried out of model effects of damping groove of the disk on the pressure pulsation. The optimized function is verified of the damping groove in a dual pump.