The invention discloses a spherical curtain wall separator forming die which comprises a lower die seat, a male die, a movable edge-pressing shell and an upper die seat, wherein the male die is fixedto the lower die seat; the male die is provided with a forming convex surface; the movable edge-pressing shell is elastically mounted to the lower die seat and positioned around the male die, and themovable edge-pressing shell is provided with an edge-pressing lower ring surrounding and exposed out of the forming convex surface; the upper die seat is provided with a female die corresponding to the male die; the female die is provided with a forming concave surface corresponding to the forming convex surface and an edge-pressing upper ring corresponding to the edge-pressing lower ring; and theedge-pressing upper ring protrudes out of the forming concave surface by 2 to 4cm. According to the invention, the male die on the lower die seat is punched by the female die on the upper die seat, then the movable edge-pressing shell is driven, spliced and stitched flanging is pressed and a separator of a spherical curtain wall is formed, so as to avoid the defects of trouble in pressing and bending and poor forming accuracy.