Electrical wire connecting device for building

The utility model discloses a building electrical wire connecting device, which comprises a shell I and a shell II, the end parts of the shell I and the shell II are hinged through a connecting piece, a support frame is arranged at the center in the shell I, a rectangular conductive metal sheet is arranged on the support frame, and the rectangular conductive metal sheet is connected with the shell II through a connecting piece. First threaded holes are symmetrically formed in the positions, located at the two ends of the conductive metal sheet, of the supporting frame, the two ends of the conductive metal sheet extend to the inner bottoms of the first threaded holes, first bolts are arranged in the first threaded holes in a matched mode, first grooves are formed in the two ends, away from each other, of the first threaded holes in a connected mode, and the first grooves extend to the two ends of the first shell. An arc-shaped face is arranged at the position, corresponding to the supporting frame, of the seco