Falling-prevention safety device of overhead door

The utility model discloses a falling-prevention safety device of an overhead door. The falling-prevention safety device of the overhead door comprises an electromagnet, wheels, brake friction sheets, a steel wire rope and a rotating shaft. The brake friction sheets are fixed on the end portion of the electromagnet, the brake friction sheets and the electromagnet are fixed on the rotating shaft, the brake friction sheets are located between the electromagnet and the wheels, one end of the steel wire rope is fixed on the wheels, and the rotating shaft is sleeved with the wheels. When the overhead door is out of control and falls fast, the falling-prevention safety device can play of a role of protection, and the overhead door is prevented from falling fast so that people cannot be hurt and objects cannot be damaged.