Hydraulic speed control loop and control method of automobile crane rotation system

The invention discloses a hydraulic speed control loop and control method of an automobile crane rotation system, the hydraulic speed control loop comprises a proportional control hydraulic valve, a rotation hydraulic motor, a pilot control hydraulic valve and a handle, the proportional control hydraulic valve is used for switching different working positions and providing hydraulic oil in different directions and flows to the rotation hydraulic motor; a pilot control hydraulic valve receives a current signal and opens a pilot valve, and oil pushes a valve element of a main valve to move and drives a rotary hydraulic motor to carry out loading movement; the handle is an operation end device used for rotation operation, the controller controls the high-speed switch hydraulic valve through PWM, when the crane is in a low-speed rotation state, the flow of hydraulic oil flowing into the rotation hydraulic motor is changed, and the rotation speed is stabilized. Conditions are created for the response speed, the st