Aiming at the zero low speed operation of synchronous reluctance motor without position sensor, an improved high frequency pulse voltage injection control algorithm is proposed. Using a Simplified First-Order Linear ADRC to Replace the PI Control in the Speed Outer Loop and the rotor position information is obtained by demodulation of the stator current αβ axis component, and a simplified linearized auto-disturbance rejection control algorithm is used to optimize the speed closed-loop control of synchronous reluctance motor. This method omits the band-pass filter used in traditional approaches, simplifying the system architecture and effectively reducing motor speed fluctuations. The experimental results show that the proposed improved high-frequency pulse voltage injection method in this study exhibits excellent steady-state and dynamic performance at low speeds. The enhanced control strategy shows superior rotor position tracking capabilities across different speeds, speed transitions, and sudden load additions in the low-speed domain. These experiments validate the feasibility and effectiveness of this control approach for synchronous reluctance motors.