The invention aims to provide a welding robot for hull block manufacturing. The welding robot comprises a track, a base, a connecting piece, a standard mechanical arm used for welding, a gun cleaning and wire cutting device, a welding and wire feeding device and a wire plate mounting device, wherein the standard mechanical arm, the gun cleaning and wire cutting device, the welding and wire feeding device and the wire plate mounting device are arranged on the base; the track stretches across a cabin block, the base is movably connected with the track, and the connecting piece is connected with the track and the block. The welding robot has the advantages of being reasonable in structure, convenient to use and controllable in cost. The position of the welding robot in a cabin can be precisely positioned, precise welding can be realized, the welding quality is ensured, the manual welding way is avoided, the working efficiency is improved, the production efficiency is improved, and the production requirement is met.