Objective To put forward an axial piston pump, the flow of which could be changed through rotating its swash-plate, to study the flow changing manner and the displacement variation rule of the pump, as well as the pulsations of the pump during flow change. Methods The mathematical model of the rotating-swash-plate axial piston pump was built, and its working principle was explored. The displacement formula of the axial piston pump was deduced, and the variation curve of the pump displacement with the rotation angle was drawn. According to the structural features of the through-shaft axial piston pump, the flow changing structure of rotating-swash-plate axial piston pump was designed. The torque of swash-plate was calculated through analyzing the force of swash-plate when it was rotated, and finally got the formula for torque. According to the single plunger instantaneous displacement analysis diagram of axial piston pump, we got the formula of single plunger instantaneous displacement, and finally we got the instantaneous flow rate simulation curve of the rotating-swash-plate axial piston pump and the varying-angle axial piston pump with the help of computer. The pulsations of the rotating-swash-plate axial piston pump and the varying-angle axial piston pump were comparatively analyzed. Results The relationship of the flow of the swash-plate axial piston pump and the angle of swash-plate rotation was a cosine relationship. When the rotation angle of the swash-plate was increased from 0 degree to 90 degrees, the pump′ s flow decreased, while the pump’ s pulsation increased. Conclusion Swash-plate axial piston pump could achieve changing and reversing its flow, but the pump′ s pulsation would change greater when adjusting the flow. In the further research, the limitation of the rotating-swash-plate axial piston pump should be overcome.