Abstract: The underground crawler detection robot has a complex working environment, and needs to carry a variety of detection or rescue equipment and climb obstacles, which easily leads to load disturbance and has strong nonlinearity and uncertainty. In addition, the permanent magnet synchronous motor (PMSM) system used for robot power drive is a multivariable and strong coupling nonlinear system, and the conventional proportional integral derivative(PID) controller based on error can not meet the control requirements. In order to solve the above problems, a four-arm underground crawler detection robot is designed, and the climbing performance is analyzed. The torque and rotational speed of robot PMSM are obtained under two working conditions of straight driving on flat ground and straight climbing. The PMSM is modeled and analyzed, the speed loop adopts the active disturbance rejection controller (ADRC), the current loop adopts proportion integration (PI) controller, and the ADRC+PI disturbance rejection control scheme is designed. The PMSM is driven by the field oriented control (FOC) technology, thereby improving the response performance and anti-disturbance performance of the robot when operating underground. The ADRC+PI control scheme and the conventional PI+PI control scheme are simulated and compared, and the speed, torque and phase current response curves of PMSM under two working conditions are obtained. The results show that under the two working conditions, when the ADRC+PI control scheme is used, the speed and torque response control of the robot PMSM is more accurate, with smaller overshoot and shorter adjustment time, and the PMSM has stronger capability to deal with external sudden disturbance. The scheme can improve the obstacle climbing performance and operation stability of the underground crawler detection robot effectively.