The invention discloses a plug-type triangular wire harness producing device including a working table, a first fixed base, a second fixed base, a connector and a fixing rack. The working table is therein provided with a motor. The upper part of the working table is provided with the first fixed base, the second fixed base and the fixing rack. A wire harness, a turnover cover plate and a positioning device are arranged in the first fixed base. The positioning device is fixedly connected to the bottom of the turnover cover plate. The bottom of the positioning device is in contact connection with the wire harness. The turnover cover plate is arranged between the wire harness and the connector. A triangular plug and a rocker arm are arranged on the inner side of the second fixed base. A turnover cover plate is arranged between the second fixed base and the connector. According to the invention, a heater is in the fixing rack and moves downward under the action of a hydraulic press, and isthus disposed between the connector and connector; the heater heats the connectors, so that the connectors are in a melting state; then the connectors are enabled to press each other and are connected fixedly after cooling, so that the service life of the wire harness is prolonged.