Automatic reposition fire-proof valve actuator

The utility model relates to an automatic resetting fireproof a valve actuator which is an actuator used for matching with a smoke exhausting valve executor or a fireproof valve actuator, and is an actuator which can cause a smoke exhausting valve or a fireproof valve to be automatically reset. A draw rod is driven by a motor after the speed of the motor is reduced, a driving slice is driven by the draw rod, and a driven slice which forms an integral body with a main shaft is driven by the driving slice to rotate. Due to the fact that the main shaft of the utility model and the main shaft of a matching actuator are engaged into an integral body, a valve vane is driven by the main shaft to carry through resetting operation when the main shaft rotates. The utility model has the characteristics of novel structure, reliable action, etc., and belongs to the automatic resetting fireproof valve actuator which integrates economy and practicability.