A fast closing mechanism includes a rotation shaft and an ejector pin. The ejector pin is rotatably assembled to the side plate by the rotation shaft. The ejector pin strides over the side plate. The ejector pin includes a first portion and a second portion. The first portion is connected to a handle via a rod, and the second portion is located above a press plate. The fast closing mechanism may have an additional ejector pin based on current structures, the press plate may press against a moving contact at an initial stage of a closing process, so that the moving contact will not move during the initial stage of the closing process. The mechanical energy generated during the closing process is stored in an energy storage spring. At a later stage of the closing process, the ejector pin releases the press plate to accomplish closing quickly.