The invention relates to the field of motor vehicle parts, and discloses a gear train of a motor vehicle door closing device. The gear train of the motor vehicle door closing device comprises a first gear and a second gear, wherein the first gear is installed on a gear shaft, the second gear is installed on a gear shaft, the axis of the first gear and the axis of the second gear are parallel, each gear shaft is installed on a gear base, guide teeth are arranged on the base of the first gear with the corresponding gear shaft as the center, three groups of gear teeth are arranged on the first gear in the axial direction in sequence from top to bottom, the three groups of gear teeth include the first gear teeth, the second gear teeth and the third gear teeth, the guide teeth are used in cooperation with the first gear teeth, and when the two gears separate, the top surface of the third gear is lower than the bottom surface of the second gear. According to the gear train of the motor vehicle door closing device, the separation and reunion between a motor and a locking clamping plate are achieved through gear combination, the volume of the lock body of a door lock is not increased, the cost is low, maintenance is easy, the gear train can be installed on any motor vehicle, and popularization and application of the apparatuses of the same kind are facilitated.