[Objective] The submersible permanent magnet synchronous motor (SPMSM) offers advantages such as high safety, reliability, efficiency, and fast response, making it an ideal replacement for low-efficiency asynchronous submersible motors. Its control performance directly affects the stability of submersible electric pumps and the efficiency of oil extraction. However, due to the harsh working conditions in oil wells, installing position sensors in submersible motors is impractical. To address this issue, this study establishes a mathematical model of the motor under high-frequency excitation and proposes a sensorless active disturbance rejection control (ADRC) strategy using the high-frequency square-wave injection method. [Methods] A filterless approach was employed to separate fundamental and high-frequency current signals, allowing the extraction of rotor position information from high-frequency current signals. To enhance the accuracy of speed estimation in the medium- and high-speed range, a Luenberger observer with error feedback correction was implemented to reduce observation errors in motor speed and rotor position. Additionally, analyzing the influence of uncertain disturbances on the system, on the basis of that, a speed regulator based on ADRC was designed and integrated into the vector control system. [Results] To verify the performance of the high-frequency square-wave injection method based on ADRC technology at low speeds, a system simulation model was developed using Matlab/Simulink. The simulation results indicated that the proposed system exhibited excellent speed-tracking performance and high rotor position estimation accuracy, with a fast dynamic response and high steady-state accuracy. Furthermore, the control algorithm effectively followed the actual speed under sudden load disturbances and restored stability within a short period, validating the effectiveness and feasibility of the proposed control strategy. [Conclusion] The proposed method successfully mitigates the impact of load disturbances across a wide speed regulation range.