Through the analysis of the physical elements of the cover shell, it is found that it possesses grooves, protrusions, and appearance elements. The cover shell is placed vertically in the injection mold, with the parting surface set on the bottom. If the gate is also set on the bottom, according to the expected analysis of defects, the plastic melt will produce countercurrent filling, resulting in defects such as insufficient filling, bubbles, overheat marks, flow marks, and silver streaks. Therefore, it is necessary to adopt concurrent filling, and the latent point gate of the mold should be set on the upper part of the cover shell. In this way, the above-mentioned defects can be eliminated and the appearance requirements can be met. The plastic melt injected into the latent runner enters the mold cavity through the point gate on the ejector pin. The condensed material in the main runner can be pulled out of the mold by the ejector pin, and the condensed material in the branch runner and latent runner can be pushed out by the ejector pin. While the ejector pin pushes out the cover shell, the condensed material attached to the point gate in the ejector pin can fall off by itself. This gating system shortens the length of the gating system, avoids the use of hot runners, and has universal application value.