A power plug, including: a shell, the shell having two sides, a reset button and a test button protruding from the first side, and a live wire pin and a neutral wire pin protruding from the second side; a circuit board; a stationary contact; a movable contact; a tripping device; a cross arm; and a push block. The stationary contact is connected with the live wire pin and the neutral wire pin; the movable contact can be connected to or disconnected from the stationary contact. The tripping device includes a sliding pedestal and a sliding part and controls the connection between the movable contact and the stationary contact. An elastic member is disposed on the push block. An ejector spring is disposed on one end of the movable armature. A reset spring is disposed between the sliding part and the sliding pedestal.