Abstracs: Sensorless control technology addresses critical limitations of conventional position sensors—including environmental susceptibility and low operational reliability—while significantly enhancing system power density, making it highly suitable for high-speed aerospace propulsion systems. The dynamic performance of sensorless control systems for high-speed permanent magnet motors (HSPMMs) is predominantly governed by advanced control strategies. Traditional sliding mode observers (SMO) exhibit inherent challenges such as chattering, phase delay, and insufficient dynamic tracking capabilities. To overcome these limitations, this study proposes a hybrid control strategy combining an adaptive super-twisting sliding mode observer (ASTSMO) and an extended state observer-based quadrature phase-locked loop (ESO-PLL). The core innovations are the ASTSMO structure effectively suppresses inherent chattering on the sliding mode surface; an adaptive law replaces the traditional low-pass filter, thereby avoiding amplitude attenuation and phase shift of the back electromotive force signal and significantly enhancing system robustness; and a fundamental frequency speed-superimposed ESO-PLL is designed to replace the traditional quadrature phase-locked loop, improving the dynamic estimation performance of position and speed. Validation was conducted based on an established simulation model of a sensorless high-speed permanent magnet propulsion system and a 9 kW high-speed propulsion motor test platform for UAVs. Results demonstrate that, compared to the traditional SMO method, the proposed composite strategy reduces speed regulation time by 33%, decreases steady-state speed fluctuation by 59%, and reduces steady-state position error by 50%. The system′s dynamic response and control accuracy are significantly improved, meeting the high dynamic response and high-precision control requirements of high-speed aviation propulsion motor systems.