Aiming at the problem of single flow control method caused by poor spring adjustability of traditional single-stage compensation valve in the proportional control circuit with pressure compensation function,a proportional control method based on the principle of variable pressure differential pressure compensation was proposed.A motor control loop with a new variable pressure differential pressure compensation unit was the research object.The control loop was simulated to obtain valve flow and pressure change law in the simulation environment,and its anti-interference characteristics and speed regulation mechanism with variable pressure compensation unit were revealed when the load changes.The simulation models correctness was verified by comparing with the experimental results.The research shows that the proposed variable pressure compensation circuit has better performance than the traditional single-stage compensation.The proportional control circuit can get a larger flow range through adjusting pressure compensation valves pilot setting.