Abstract: In this paper,the water lubrication swash-plate axial water hydraulic piston motor with floating valve plate was developed.It is working pressure is 10 MPa,output rating torque is 12.5 N·m,and rating speed is 1 500 r/min.The motor structure characteristic was introduced,and experimental research on the self-development comprehensive test system was done for the water hydraulic piston motor.The performance verification tests were also made.The analysis was done for motor displacement,motor flow and efficiency et al.The experimental results prove the structure design correctness.