The invention discloses a circular electric connector, and relates to the technical field of electric connectors. A dustproof cap sealing gasket is provided with a chain. The left side of the dustproof cap sealing gasket is provided with a locking handle. A plug insulator cover plate, a jack upper insulator, a plug rear cover plate and a rear cover plate sealing gasket are arranged on the outer surface of the locking handle. A jack is inserted into the plug insulator cover plate and the jack upper insulator. A sheath is disposed outside the jack. A positioning sleeve is disposed outside the jack upper insulator. One end of the positioning sleeve is equipped with an insulator sealing ring. The plug rear cover plate is fixed to a cable cover through a grooving cylindrical screw. A waterproof rubber plug is arranged below the cable cover. A tightening sleeve is disposed below the waterproof rubber plug. A wire clamp press plate is disposed below the tightening sleeve. A wire clamp body is arranged on the inner side of the wire clamp press plate. A central screw is adopted for connection. The circular electric connector is simple and quick to connect, convenient to use and easy to operate, and enables the work efficiency to be improved and the time to be saved.