The 96-cavity ultra-thin side-gate hot runner system is specifically developed for the mass production and precision injection molding of disposable syringe plungers. It features an ultra-thin flat structure and a side-hidden gating design, which significantly reduces the overall installation height and the space occupied by the mold. This simplifies the mold plate structure and cuts down on mold steel materials and processing costs. With an ultra-high-cavity layout of 96 cavities in one mold, the molding efficiency is doubled. It is suitable for medical-grade PP raw materials and meets the medical injection-molding standards for syringe plungers, such as being straight without deformation, having a flat end-face, no gate scars, and high consistency in mass production.