The invention discloses a welding assembly. The welding assembly comprises a base and further comprises a shaping mechanism, a horizontal moving and rotating mechanism and a welding mechanism. The shaping mechanism comprises an L-shaped fixing plate which is fixed to the back surface of the base and located above the left portion of the horizontal moving and rotating mechanism, an L-shaped mounting plate connected to the lower surface of the tail end of the L-shaped fixing plate through bolts, a shaping cylinder fixed to the outer surface of the tail end of the L-shaped mounting plate, and a shaping clamping jaw fixed to an output shaft of the shaping cylinder. Two first long strip-shaped holes are formed in the L-shaped fixing plate. A first threaded hole is formed in the L-shaped fixingplate. The L-shaped fixing plate is locked in the first threaded hole of the L-shaped fixing plate through bolts penetrating through the first long strip-shaped holes. The horizontal moving and rotating mechanism comprises a servo electric cylinder, a moving block, an L-shaped connecting block, a sliding block and a rotating cylinder, wherein the servo electric cylinder is arranged on the back surface of the base, the moving block is fixed to the servo electric cylinder, the L-shaped connecting block is fixed to the front surface of the moving block, the sliding block is fixed to the rear endof the L-shaped connecting block, and the rotating cylinder is fastened at the front end of the L-shaped connecting block.