Abstract: In response to the problems of poor dynamic adaptability and parameter sensitivity of the PI controller commonly used in the speed loop of emulsion pump station systems with permanent magnet synchronous motors, this paper constructs a sliding mode controller in the speed loop to improve the stability and robustness of the system, and proposes a new approach law based on traditional sliding mode to further solve the problems of slow response time and chattering near the sliding mode surface in traditional sliding mode systems. Then, an extended state observer is added to the integral sliding surface to compensate for unknown disturbances and load torque in the system through feedforward compensation. The simulation of the sliding mode control strategy designed based on the proposed approach law shows that this strategy can enable the system to quickly respond to the expected trajectory and achieve better stability on the sliding mode surface. The experimental results further prove that the improved strategy proposed in the paper has a good optimization effect on improving the system response speed and the chattering of the sliding mode itself.