Splicing and mounting device for rear cross beam assembly

The utility model discloses a rear cross beam assembly splicing installation device which comprises a workbench, and a bolt box is installed on one side of an installation plate. Bolts are evenly placed in the bolt box in the longitudinal direction, a through hole is formed in the position, corresponding to the bolt box, of the bottommost bolt, an electric wrench is installed at the bottom end of the bolt box, an inner hexagonal sleeve is installed at the output end of the electric wrench, and a blocking piece is fixed to the top end of the workbench and comprises a fixing block. A nut box is arranged on the fixing block, nuts are evenly placed in the nut box in the longitudinal direction, a preformed hole is formed in the position, corresponding to the nut box, of the bottommost nut, a bolt can be pushed into a mounting hole by starting a second air cylinder and a third air cylinder and adjusting the position of a bolt box, and an inner hexagonal sleeve is clamped at the head of the bolt. And then the electr