The utility model discloses prefabricated wall connecting joint that separates, including prefabricated partition wall, metal angle bead, waterproof layer, C25 plain concrete layer and connecting piece, connecting piece include two dorsad the U groove that sets up of interval with be used for two connecting plates of linking together of the U groove that sets up of interval dorsad, prefabricated partition wall has the four sides and sets up the U inslot that sets up of interval dorsad connecting plate both sides and two and the tip of prefabricated partition wall is do not laminated, prefabricated partition wall section is cross -shaped structure, and the contained angle department between the adjacent prefabricated partition wall is provided with the metal angle bead, and the metal anglebead passes through self -tapping screw to be fixed on prefabricated partition wall, the waterproof layer laminating sets up on the metal angle bead, metal angle bead and waterproof layer that the C25plain concrete layer will set up on prefabricated partition wall wrap inside. The utility model discloses prefabricated partition wall linking department does not have the gap, and the waterproof while provides strong support for the prefabricated partition wall of cross diaphragm structure. Prefabricated partition wall is durable, has higher stability.