[Objective] High-precision vector control of permanent magnet synchronous motor (PMSM) faces problems such as dependence on position sensors, response lag of sudden load change, and start-up out-of-step. During PMSM operation, the time-varying factors such as stator internal resistance partial voltage, back electro motive force and dq-axis coupling term will degrade the control accuracy. [Methods] In order to meet the demands of high-precision applications, this paper proposed a method integrated speed identification, load disturbance suppression, and precise magnetic field orientation for speed sensorless control. Firstly, a model reference adaptive system (MRAS) was constructed based on Popov superstability theory, and an adaptive law was designed to identify the speed through the output error of the reference model and the adjustable model of the stator voltage equation to achieve the speed sensorless operation. Secondly, a full order state observer (FOSO) was constructed based on MRAS. The system state space was reconstructed by using the measured voltages, currents and the estimated rotational speeds. A feedback gain matrix was configured to suppress speed fluctuations caused by sudden load changed, forming a virtual speed loop to enhance disturbance rejection capability. Finally, open-loop starting was used to solve the motor out-of-step problem caused by the randomness of rotor position during motor starting, the stator internal resistance voltage division compensation and the dynamic compensation of dq-axis cross-coupling term were introduced into the dq-axis control voltage, which reduced the control voltage loss and realized the precise orientation of the stator magnetic field. [Results] The experimental results showed that the virtual speed ring composed of FOSO could effectively suppress the load disturbance, and the magnetic chain circle after the precise magnetic field orientation was closer to the ideal circle. [Conclusion] The integrated control method proposed in this paper effectively solves the control difficulties of PMSM in the areas of speed sensorless operation, response lag of sudden load change and start-up out-of-step, and significantly improves the system response speed and control accuracy.