The present disclosure provides an inductance detection method includes steps of: (a) acquiring a stator resistance of the reluctance motor; (b) injecting a high-frequency sinusoidal signal in the d-axis or q-axis direction; (c) injecting an align signal command in the q-axis or d-axis direction; (d) receiving a dq-axes signal generated through injecting the high-frequency sinusoidal signal and the align signal command; (e) sampling a motor feedback signal generated through receiving the dq-axes signal; (f) in the direction of injecting the high-frequency sinusoidal signal, calculating an amplitude difference between the high-frequency sinusoidal signal and the motor feedback signal, and adjusting an amplitude of the high-frequency sinusoidal signal according to the amplitude difference for regulating a feedback amplitude of the motor feedback signal; and (g) when the feedback amplitude reaching an expected amplitude, calculating an apparent inductance of the reluctance motor based on the dq-axes signal, the motor feedback signal and the stator resistance.