A 2-phase outer ring switched reluctance motor is suitable for use as a low-speed and high-flow rate fan, causes a difference in electrical angle of 180° when two armatures are fitted and coupled along an axial direction at the upper and lower sides thereof one by one and eliminates the difference in electrical angle when two outer ring rotors are fitted and coupled along an axial direction at the upper and lower sides thereof one by one, so as to enable the same to be easily assembled into a 2-phase motor and ensure a firm assembled state, simplifies a structure for detecting an excitation section by modularization in which sensors are provided at each armature and objects to be sensed are provided for each outer ring rotor, and escapes from an unstartable state by using a forward rotation sensor and a reverse rotation sensor.