An automatic sucking closing mechanism for an automobile door lock comprises a shell. A dragging arm, a locking claw and a clamping plate are arranged in the shell. The locking claw is located betweenthe dragging arm and the clamping plate. The middle of the dragging arm is rotationally connected into the shell through a connecting shaft. A dragging conversion arm is rotationally connected with the upper portion of the dragging arm through a hinge shaft. The lower portion of the locking claw is rotationally connected into the shell through an intermediate shaft. A clamping groove is formed inthe side face, facing the clamping plate, of the locking claw. The clamping plate is rotationally connected into the shell through a rotary shaft. A first clamping head and a second clamping head arefixedly connected with the side portion of the clamping plate in a spaced mode. A check block located on one side of the end of the dragging conversion arm is fixedly connected with the side portionof the clamping plate. A driving device for driving the dragging arm to rotate around the connecting shaft is arranged on one side of the shell. The automatic sucking closing mechanism is simple in structure, safe, reliable, high in practicability and low in manufacturing cost, operation of automatic sucking closing to the full-locking state can be achieved under the partly-locking state of an automobile door, a user does not need to open the automobile door and close the automobile door again, operation is convenient, and the automatic sucking closing mechanism is easy to apply and popularize.