The constant pressure variable pumps are widely used in practical applications, including hydraulic systems of aircrafts and heavy machines. While if the pump pressure is variable, then the efficiency can be increased and the flexibility for usage can be improved. In this paper, a stepless variable pressure pump based on high-speed on-off valves is proposed. The main idea is using electromagnetic high-speed on-off valves as pilot valves for the axial piston pump. The pump can be set to the required pressure, compared with pressure signal detected by pressure sensor, to control the switch valves and the swash plate angle of the piston pump. Therefore, compared with pumps using proportional or servo valves as pilot valves, the system proposed here has lower requirements for oil contamination. The software AMESim and Matlab/Simulink are employed to model the system. The continuously variable pressure is obtained in the simulation, and the robustness to the disturbance of the hydraulic load is investigated as well. The stepless variable pressure axial piston pump may have advantages of flexibility for different working conditions and high efficiency for total working cycle.