The invention relates to a device for releasing and resetting a fire and smoke barrier. In a normal use state, a clutch member is held by an electromagnetic attraction unit, so that a push rod ejecting module cannot be actuated, and a door operator is controlled by a clutch module thereof. Upon power failure, for example upon an accident, the clutch member is released by the electromagnetic attraction unit, and a barrier release member is activated by the push rod ejecting module so as to shut the fire and smoke barrier. Upon power restoration, the clutch member is attracted and held by the electromagnetic attraction unit, and the push rod ejecting module is reset by a push rod resetting module. At the same time, the barrier release member is also reset.