A manufacturing method of a middle frame for a display screen, a display screen and a display device is provided. The method includes: fixing a glass cover plate of the display screen to a first mold; bonding a second mold with the first mold, so as to form a cavity for forming the middle frame on a periphery of the glass cover plate; injecting a molten material into the cavity; cooling the molten material to form the middle frame, wherein the middle frame is integrally injected and molded on the periphery of the glass cover plate.