Traditional noise reduction method for axial piston pump by optimizing the transition area in the valve plate is based on specific structural parameters, which is of less meaning for valve plate design. The formation mechanism of the noise excitation sources of hydraulic noise and structural noise for axial piston pump was discussed. Then, aiming at elimination of the pressure overshoot in piston chamber, and control of the peak value and position of backflow into piston chamber, a forward design theory of distribution method with damping orifice and damping groove for axial piston pump was proposed. Finally, a valve plate was designed based on this design theory. The noise reduction effect of this valve plate was analyzed. Results showed that the application of this design method could reduce the flow ripple amplitude apparently and the pressure overshot could be almost eliminated. Because the structure of the damping groove was not appointed, this design theory can be used in the valve plate design of different domestic axial piston pumps.