Abstract: Tandem mold as a new molding technology can fully tap the potential of the injection molding machine, but the application of tandem mold is less interiorly. In this paper, tandem mold was introduced into the molding of plastic tubing coupling, and the tandem mold was designed in combination with the structural characteristics of 90° electric melting elbow PE pipe fitting. The tandem mold structure was composed of an upper and lower two-layer mold with one mold and two cavities. A needle-valve type hot runner system was designed to achieve alternate injection and holding. The T-lock with cylinder was designed to cooperate with the CAM plate to realize sequential mold opening and core pulling. The production results show that the use of tandem mold molding technology can greatly reduce the inactivity time of the injection molding machine and reduce the time cost of a single product.