Slag blowing pipe welding tool and welding method thereof

The invention provides a slag blowing pipe welding tool and a welding method thereof.The slag blowing pipe welding tool comprises two symmetrically-arranged clamping bases, two clamping bases, a welding rod, a welding rod, a welding rod and a welding rod, and the two clamping bases are used for fixing the two ends of a steel pipe in a butt-clamping mode; the heights of the supporting blocks decrease progressively from the middle to the two sides, and the supporting blocks are used for supporting the steel pipe and enabling the steel pipe to be arched upwards. The steel pipe is fixed firstly and bent downwards, and then the nozzle is welded to the upper end of the steel pipe; after the steel pipe is loosened, the deformation direction generated by welding is opposite to the bending direction before welding, and the deformation quantity generated by welding just compensates for the bending quantity before welding, so that the steel pipe is in a linear state after welding is completed; the process of straighteni