The invention discloses a method for detecting an initial
magnetic field position of a linear
synchronous motor. A motor is controlled by using a three-phase
inverter of a
servo controller; a
system is electrified; under the control of the
servo controller, a V-phase upper bridge arm and a W-phase lower bridge arm of the three-phase
inverter are conducted, and other bridge arms are
cut off; at the moment, a current sequentially flows through the V-phase upper bridge arm, a V-phase winding of the motor, a W-phase winding of the motor and the W-phase lower bridge arm; by using common ends of three-phase windings of the motor as reference points, a
positive current flows through the V-phase winding of the motor, and a negative current flows through the W-phase winding of the motor; and after the motor stops rotating, the
servo controller acquires a motor position
signal which is fed back by an incremental photoelectric coder, and a motor position serves as the initial
magnetic field position of the motor. By adoption of the method, the initial
magnetic field position of the motor can be simply, conveniently and quickly detected, a large amount of calculation of a
microprocessor of the servo controller is avoided, and detection accuracy and the control speed of the servo controller are improved.