The invention discloses a mold for molding an arch-shaped workpiece. The mold comprises a fixed mold, multiple outer mold cores, multiple inner mold cores, inclined ejectors and an ejector pin plate assembly. The fixed mold is provided with a pressing block, and the pressing block is provided with a limiting face extending in the front view direction. The multiple outer mold cores are used for molding outer side faces of the arch-shaped workpiece. The multiple inner mold cores are used for molding inner side faces of the arch-shaped workpiece; the back side of each inner mold core is providedwith a back face and a guiding face, wherein each back face and the side direction are arranged in a face-to-face manner, and each guiding face extends in the side direction; and each back face is provided with multiple ejection holes. The inclined ejectors are fixedly connected with the inner mold cores and used for ejecting the inner mold cores inwards in an inclined manner in the front view direction. The ejector pin plate assembly comprises a base plate, a panel and an ejector pin; the base plate and the panel are matched with the guiding faces in a sliding manner; the panel is located between the back faces and the base plate; and the edge, close to each inclined ejector, of the base plate is provided with an inclined face which is inclined inwards in the front view direction. By means of the mold for molding the arch-shaped workpiece, smooth demolding of the arch-shaped workpiece in a narrow and small space can be achieved, and thus integrated molding of the arch-shaped workpiececan be achieved conveniently; and the manufacturing process can be simplified, and the production cost can be saved.