The invention discloses a module assembly anti-deformation and welded junction fitting-up wedge-shaped tool which comprises a wedge-shaped tool fixed block and wedge-shaped adjusting part. The wedge-shaped tool fixed block is of an L-shaped structure, and the lower surface of the vertical portion of the L-shaped structure is a first mounting surface; the lower portion of the transverse portion of the L-shaped structure is provided with a first oblique surface, the surface, opposite to the first oblique surface, of the wedge-shaped adjusting part is provided with a second oblique surface, and the first oblique surface is parallel to the second oblique surface; when assembly is conducted on the two modules to be welded, the wedge-shaped adjusting part can move to the direction of the wedge-shaped tool fixed block along the first oblique surface; when the assembly is finished, the portion, without making contact with a second module to be welded, of a second mounting surface of the wedge-shaped adjusting part is attached to the upper surface of a first module to be welded, and the first module to be welded is in butt joint with the second module to be welded. By means of the module assembly anti-deformation and welded junction fitting-up wedge-shaped tool, the unfitness of butt joint of the welded junction between the modules can be adjusted conveniently, and it can be guaranteed that the unfitness of butt joint of the welded junction is within 1 mm.