The invention relates to a brushless DC motor stator winding phase sequence, a corresponding relation determining method of a stator winding phase sequence and a coder and a detection device. In the method, based on a counter electromotive force potential zero-crossing point and a phase changing point (a coder output signal ascending edge and a descending edge) among stator windings, a stator winding phase sequence is determined according to a voltage zero-crossing point sequence among the stator windings, and the corresponding relation of a coder interface and the stator windings is determined according to the corresponding relation of the stator winding zero-crossing point and the coder output signal ascending edge or descending edge. By using a microprocessor system as an operation processing unit, the device detects the voltage zero-crossing point among the stator windings and the coder output signal ascending edge and descending edge by combining a peripheral hardware detecting unit, and the phase sequence judgment and the corresponding relation of the phase windings and the coder interface are completed once. In the invention, the problems caused by electrical angle delay are avoided, the detection steps are direct and accurate, and the detection device has simple structure and is suitable for detecting and judging a brushless DC motor.