A method for estimating a rotor position of a synchronous motor, comprising: obtaining a position error signal by injecting a high-frequency signal into a stator winding of the motor; obtaining a load parameter indicating a load of the motor, obtaining a direct-current component disturbance value according to the load parameter and a first preset relationship, obtaining a harmonic component disturbance value according to the load parameter and a second preset relationship, and obtaining an observer parameter value according to the load parameter and a third preset relationship; compensating the position error signal or an associated signal of the position error signal according to the direct-current component disturbance value and the harmonic component disturbance value to obtain a compensated position error signal; and adjusting an observer parameter according to the observer parameter value, and adjusting the compensated position error signal through an adjusted observer to obtain the rotor position and a rotor speed; wherein the load parameter is a q-axis average current in an estimated rotor coordinate system; wherein in condition that the high-frequency signal is a 45-degree axis demodulated pulse signal, obtaining the position error signal comprises: collecting a current of a stator winding, and obtaining a d-axis current and a q-axis current in a 45-degree estimated dq coordinate system by performing a coordinate transformation on the current of the stator winding; obtaining a first deviation current by calculating a difference between the d-axis current and the q-axis current in the 45-degree estimated dq coordinate system, and obtaining a filtered first deviation current by band-pass filtering the first deviation current; and obtaining a first current response signal by multiplying the filtered first deviation current with a first preset signal, and obtaining a second current response signal by low-pass filtering the first current response signal; wherein the first preset signal is determined according to the high-frequency signal, and the second current response signal is a direct-current portion of the first current response signal; wherein the first current response signal is the associated signal of the position error signal, and the second current response signal is the position error signal. obtaining a position error signal by injecting a high-frequency signal into a stator winding of the motor; obtaining a load parameter indicating a load of the motor, obtaining a direct-current component disturbance value according to the load parameter and a first preset relationship, obtaining a harmonic component disturbance value according to the load parameter and a second preset relationship, and obtaining an observer parameter value according to the load parameter and a third preset relationship; compensating the position error signal or an associated signal of the position error signal according to the direct-current component disturbance value and the harmonic component disturbance value to obtain a compensated position error signal; and adjusting an observer parameter according to the observer parameter value, and adjusting the compensated position error signal through an adjusted observer to obtain the rotor position and a rotor speed; wherein the load parameter is a q-axis average current in an estimated rotor coordinate system; wherein in condition that the high-frequency signal is a 45-degree axis demodulated pulse signal, obtaining the position error signal comprises: collecting a current of a stator winding, and obtaining a d-axis current and a q-axis current in a 45-degree estimated dq coordinate system by performing a coordinate transformation on the current of the stator winding; obtaining a first deviation current by calculating a difference between the d-axis current and the q-axis current in the 45-degree estimated dq coordinate system, and obtaining a filtered first deviation current by band-pass filtering the first deviation current; and obtaining a first current response signal by multiplying the filtered first deviation current with a first preset signal, and obtaining a second current response signal by low-pass filtering the first current response signal; wherein the first preset signal is determined according to the high-frequency signal, and the second current response signal is a direct-current portion of the first current response signal; wherein the first current response signal is the associated signal of the position error signal, and the second current response signal is the position error signal. collecting a current of a stator winding, and obtaining a d-axis current and a q-axis current in a 45-degree estimated dq coordinate system by performing a coordinate transformation on the current of the stator winding; obtaining a first deviation current by calculating a difference between the d-axis current and the q-axis current in the 45-degree estimated dq coordinate system, and obtaining a filtered first deviation current by band-pass filtering the first deviation current; and obtaining a first current response signal by multiplying the filtered first deviation current with a first preset signal, and obtaining a second current response signal by low-pass filtering the first current response signal; wherein the first preset signal is determined according to the high-frequency signal, and the second current response signal is a direct-current portion of the first current response signal; wherein the first current response signal is the associated signal of the position error signal, and the second current response signal is the position error signal.