The invention relates to a rotor angle subdivision method for a switched reluctance motor speed regulation system. The method comprises the following steps, which are realized based on software, of: a, calculating a current rotor rotating speed according to a position signal of a rotor of a switched reluctance motor; b, looking up a table to acquire a switch-on angle and a switch-off angle of each phase according to a desired rotating speed and a torque value of the system; c, calculating a counting frequency of a universal timer according to the current rotor rotating speed, modifying a corresponding bit of a control register of the universal timer, and assigning a counting register of the universal timer; and d, when the counting register of the universal timer counts to a certain switch-on angle or a certain switch-off angle, switching on or switching off the phase. The rotor angle subdivision method for the switched reluctance motor speed regulation system is realized based on thesoftware. Compared with the conventional method, the method has the advantages that: the interference capacity is high, the reliability is high, and high-frequency input signals can be detected accurately; furthermore, the subdivision precision of a rotor angle is extremely high; and a driving control circuit is simple and the cost is low.