The invention discloses a differential control method and device for material crushing equipment. After the current rotating speed of a first motor used for driving a first rotary shaft of the material crushing equipment to rotate, and the current rotating speed of a second motor used for driving a second rotary shaft of the material crushing equipment to rotate are obtained, if the ratio of the current rotating speed of the first motor to the current rotating speed of the second motor is smaller than the preset value, a driving signal of a first frequency converter connected with the first motor and a driving signal of a second frequency converter connected with the second motor are adjusted so that the ratio of the driving signal of the first frequency converter to the driving signal of the second frequency converter can be increased; and specifically, the preset value is larger than one, and the influence on the material crushing effect can be reduced when the speed difference of the two rotary shafts is changed.