Soft start control method and system used for direct current motor of refrigerator

The invention discloses a soft start control method and system used for a direct current motor of a refrigerator, wherein the direct current motor is connected with a power supply through a controllable switch, and the controllable switch is used for controlling an input voltage of the direct current motor. The method comprises the following steps of: when the direct current motor enters a first start stage, controlling the controllable switch with a PWM signal of a first preset duty ratio so as to enable a first voltage to be input into the direct current motor; when the direct current motor enters a second start stage, adjusting the duty ratio of the PWM signal according to a preset rule, and controlling the controllable switch according to the adjusted PWM signal so as to adjust the input voltage of the direct current motor; and when the direct current motor enters a third start stage, controlling the controllable switch with the PWM signal of a second preset duty ratio so as to enable the direct current m