Variabledisplacement asymmetric axial piston pump (VDAAPP) directly control single piston rod hydraulic cylinder closed loop system has the advantages of compact structure and high energy efficiency. In order to develop VDAAPP, according to the fixeddisplacement asymmetric axial piston pump with three flow distribution windows, a PD variable displacement control scheme based on position feedback of swashplate angle was proposed. The mathematical model of VDAAPP was established. The factors affecting the frequency response of VDAAPP were analyzed by using approximate linearization and order reduction methods. The resistance torque of swashplate was also studied. The electrohydraulic simulation model of VDAAPP was established in AMESim. The correctness of the resistance moment formula was verified by simulation analysis of force characteristics of swashplate. The experimental platform of VDAAPP was built to test the dynamic performance of the system. The results of experiment and simulation showed that when VDAAPP sucked oil by one flow distribution window and discharged oil by two flow distribution windows, the VDAAPP swashplate had a large oneway resistance moment, which would reduce the dynamic response of the swashplate in the process of reducing the swashplate angle; when the PD control was used and the proportional gain kp was 3, VDAAPP can achieve zero overshoot variable displacement control and had high response speed, which demonstrated the rationality of the proposed control scheme.