The invention belongs to the field of stepping motor control, and specifically relates to an acceleration and deceleration control method of a stepping motor with a variable micro-stepping number. The acceleration and deceleration control method comprises the steps of (1) setting basic parameters and determining an acceleration and deceleration operation mode of the stepping motor; (2) determining the minimum micro-stepping number Nmin required for operation in the next step through the turned angle alpha and the parameters set in the step (1); and (3) calculating single-step operation time Ti according to the Nmin obtained in the step (2), generating a control pulse by taking the time as a cycle, controlling operation of the stepping motor and updating the turned angle alpha after single-step operation is completed. The invention provides the acceleration and deceleration control method of the stepping motor with the variable micro-stepping number, so that the stepping motor can be accurately located, the time that a system reaches a desired angle is shortened on the basis of preventing out-of-step and overshoot phenomena, fast operation of a stepping motor system is accelerated and the method is simple and easy to implement.