The invention belongs to the plastic molding or connecting field, especially relates to a technology for making an integrated body through injection molding, and an apparatus thereof, and concretely relates to a medical EVA inner bottle cap injection molding technology and a die thereof. The injection molding technology is designed against the characteristics of the complex structure of an EVA inner bottle cover, high health standards of a medical apparatus, and high requirements of injection molding technologies and dies thereof, and the injection molding technology comprises the steps of die locking injection, separation of an aggregate from a sprue bush, main (branch) channel opening, separation of a plastic member from a cavity, and plastic member push. The injection molding die developed in the invention comprises a fixed die holder, a cavity plate, a member pushing plate, a core, a core fixing plate, a supporting plate, the sprue bush, a movable die holder, a push plate, a cooling water channel, a groove possessed guide pillar and a keyway possessed guide pillar. The adoption of point sprue injection in the invention is benefit for the die filling flow of an EVA melt; the selection of forced demolding based on the good elasticity of the EVA avoids the inner side core extraction and saves the die cost; and 32-cavity high-quality massive production of one die is realized.