The invention discloses an automatic safety belt. The automatic safety belt includes a seat, the seat includes a seat cushion and a backrest, and a rotating shaft is installed in the seat cushion; theautomatic safety belt further comprises a rotating frame disposed outside the backrest, a gear motor and a cover cap, wherein the gear motor and the cover cap are fixedly mounted on both sides of theseat cushion correspondingly; one end of the rotating shaft is connected to the gear motor, and the other end of the rotating shaft is fixedly connected with a rotating disc disposed in the cover cap; a first micro switch and a second micro switch are arranged in the cover cap; a sliding groove formed between two belt wheels is internally provided with a plurality of guiding wheels for guiding abelt; a sliding block is mounted on a groove opening of the sliding groove, and the sliding block is fixedly connected with the belt, and a third micro switch and a fourth micro switch are mounted onguide rails at both ends of the sliding groove correspondingly; and drive motors are mounted on one ends of the guide rails. The automatic safety belt further comprises a single chip microcomputer. The first micro switch, the second micro switch, the third micro switch and the fourth micro switch transmit signals to the single chip microcomputer, and the single chip microcomputer controls the gearmotor and the drive motors. The automatic safety belt can automatically bind passengers forcibly to ensure the safety of the passengers.