Motor constant current control method and system and cleaning equipment with motor constant current control system

The invention relates to a motor constant current control method, a motor constant current control system and cleaning equipment with the motor constant current control system. The method comprises the following steps: acquiring real-time sampling current when a motor in the cleaning equipment is started to work; according to the real-time sampling current, judging whether the motor has an overcurrent abnormal phenomenon or not; and when an overcurrent abnormal phenomenon occurs in the motor, the PWM signal duty ratio of the motor is adjusted by an equal difference decreasing method, and the motor is controlled according to the adjusted PWM signal duty ratio, so that the real-time sampling current of the motor is constantly in a preset safety value range. In the working process of the motor of the cleaning equipment, when overload or stalling of the motor occurs, the current of the motor is reduced so as to keep the current of the motor in a constant range, so that the motor and a driving circuit are protecte