A pulsating high-frequency voltage injection-based sensorless control strategy for permanent magnet synchronous motor (PMSM) based on a three-parameter notch filter (TPNF) was proposed to address the increased filtering delay, reduced observation accuracy and degraded dynamic performance caused by low-pass and band-pass filters in traditional pulsating high-frequency voltage injection methods for sensorless control of PMSM in the low-speed range. Based on analyzing the impact of filters in the signal processing stage on system performance, the TPNF was used to replace the low-pass filter to enhance the attenuation of injected high-frequency AC components in the system, while increasing the current loop bandwidth, and improving position estimation accuracy. Additionally, a fourth-order generalized integrator (FOGI) was used to replace the band-pass filter to extract high-frequency signals containing position information, further reducing the impact of filtering delay on position estimation accuracy and improving estimation accuracy. This approach enabled precise rotor position tracking and enhanced the system’s dynamic performance. Simulation and experimental results indicate that the proposed strategy achieves superior rotor position estimation accuracy and dynamic response compared to traditional methods under motor startup, sudden load application, and load-carrying speed variation conditions, effectively improving PMSM control performance at low speeds.