The present invention relates to a permanent magnet synchronous motor, and discloses a method of obtaining the quadrature-axis and direct-axis inductance of the permanent magnet synchronous motor for realizing the situation of suggesting to obtain the quadrature-axis and direct-axis inductance of the permanent magnet synchronous motor. The method of the present invention comprises the steps of placing the motor on a stable table-board to stand the motor, and using a bridge to test the linear inductance value between every two of the three ends of a compressor, wherein there are existed three sets of linear inductance values; according to the principle that the difference value of the three line-between inductance values should be 120 degrees in a sine wave on the condition of determining the position of a rotating shaft, establishing an equation set about the line-between inductance values, the amplitude of a line-between inductance sine wave and the offset amount of the sine wave; solving the equation set to obtain the amplitude of the line-between inductance sine wave and the offset amount of the sine wave; according to the amplitude of the line-between inductance sine wave and the offset amount of the sine wave, obtaining the quadrature-axis and direct-axis inductance of the permanent magnet synchronous motor. The method of the present invention is suitable for obtaining the quadrature-axis and direct-axis inductance of the permanent magnet synchronous motor.