A method of obtaining a mechanical position of a motor for an ESC includes obtaining magnetic field strengths of two or more Hall sensors respectively and determining the mechanical position of the motor based on the magnetic field strengths of the two or more Hall sensors. The magnetic field strengths are obtained by measuring a magnetic leakage of two or more pairs of magnetic poles by the two or more Hall sensors. The motor includes two or more Hall sensors and two or more pairs of magnetic poles. The motor is connected to the ESC; a phase difference between the two or more Hall sensors is a preset angle; and arrangements between each pair of magnetic poles and the two or more Hall sensors are different.