Based on the theory of rotor dynamics, the rotational performance of bearing rotor system of highspeed and highpressure axial piston pump was studied. The bearing rotor system component of axial piston pump was taken as the research object, the rotor system model was built, the lumped parameter model of the rotor system was built, and the critical speed of the hydraulic pump rotor system was analyzed by finite element method. Finally, the design opinion for rotating components was given. The research results provide reference for exploring the vibration mechanism of axial piston pump and realizing precise vibration control.