The invention discloses a gas-shielded stainless steel flux-cored wire for a boiler burner, and a production process thereof. The flux-cored wire is composed of an extra-low-carbon stainless steel strip and a flux core wrapped in the steel strip. The production process comprises the following steps: wrapping the flux core in the extra-low-carbon stainless steel strip through a precise forming process, and then preparing the flux-cored wire through finish broaching diameter reduction, surface treatment and close-packed precision winding. The gas-shielded stainless steel flux-cored wire for the boiler burner, which is developed by the invention, is capable of welding S30815 austenitic stainless steel castings and forgings, and a welding joint thereof is high in creep deformation-resistant capacity and creep rupture strength, great in high-temperature corrosion-resistant capacity and erosion corrosion-resistant capacity in most of gas mediums, and high in yield strength and tensile strength and enough in machinability at a high temperature. The gas-shielded stainless steel flux-cored wire for the boiler burner is high in deposition efficiency, more beautiful compared with solid welding wire forming, easier in welding condition setting, and easy for semiautomatic and automatic welding.