Abstract: Aiming at the problems of low system reliability and high maintenance cost brought by the current permanent magnet external rotor hoist relying on mechanical position sensors, a position sensor-less control strategy integrating multi-body dynamics modeling is proposed. Firstly, the mathematical model of the permanent magnet external rotor hoist is constructed, and the theoretical analysis of the pulse vibration high-frequency signal injection method is carried out. Second, the position sensor-free control model is constructed based on a double closed-loop id = 0 vector control system, and a phase-locked loop (PLL) position observer is used to realize the dynamic observation of rotor position. Then, a multi-body dynamics model of the hoist containing the elastic deformation of the wire rope and the drum winding effect is constructed using RecurDyn software to accurately characterize the time-varying properties of the system load. Finally, a multi-domain co-simulation platform is built based on Matlab/Simulink and RecurDyn to construct an electromechanical coupled co-simulation model to validate the position sensorless control system. The joint simulation results show that under the time-varying motor load torque condition, the proposed position sensor-less control strategy realizes the control motor speed tracking error within ±0.2r/min, and the rotor position observation error is less than 0.01rad, which shows good rotor position observation accuracy and speed tracking performance during the full operation cycle of the permanent magnet external rotor hoist.