The utility model relates to a plastic middle frame injection mold and a middle frame structure. The plastic middle frame injection mold comprises a front mold structure and a rear mold structure, therear mold structure comprises a rear mold core, an injection molding hole formed in the rear mold core, a rear mold cavity parting surface and a rear mold inner parting surface, and the rear mold cavity parting surface and the rear mold inner parting surface are arranged on the rear mold core; the front mold structure comprises a front mold core, a front mold cavity parting surface and a front mold inner parting surface, wherein the front mold cavity parting surface and the front mold inner parting surface are arranged on the front mold core, and the front mold inner parting surface right faces the rear mold inner parting surface. A cavity structure communicated with the injection molding hole is defined between the front mold cavity parting surface and the rear mold cavity parting surface, and an exhaust cavity communicated with the cavity structure is defined between the front mold inner parting surface and the rear mold inner parting surface; the front mold cavity parting surface comprises a first front mold cavity inner parting surface which is adjacent to and parallel to the front mold cavity inner parting surface, and the first front mold cavity inner parting surface and thefront mold cavity inner parting surface are arranged in a staggered manner. According to the scheme of the utility model, the cost is low, and burrs are not generated on the parting surface to influence the product quality.