Because the side-blown protection effect in the laser welding is insufficient, and its convenience and flexibility are restricted. Laser welding coaxial protection nozzle is designed and trial-manufactured. According to the characteristics of laser welding protection, through rational design of nozzle structure, two protection gases are respective controlled .Using the coaxial nozzle for stainless steel laser stitch welding test, its influence on protect effect and the welding process are analyzed. The result indicates that the structure of nozzle’s gas path, gas outlet designed reasonable, venting uniform, protection effect is good. And it can reduce welding splash to focus lens, has certain protection effect.