The utility model relates to a fixing, protecting and cooling device for welding, which comprises two fixing plates, a circulating groove and a nozzle, the nozzle is communicated with the outside, thefixing plates are fixedly connected with heat conducting plates for sealing the circulating groove, and each fixing plate is provided with an input hole for introducing gas into the circulating groove. Inert gas enters the fixed plate along the input hole; the inert gas is positioned in the circulating groove; still further ejection from a nozzle, forming a gas flow, in the process, the heat of the heat affected zone is reduced under the guiding action of the heat conducting plate, so that the heat is transferred into the circulating groove and then transferred into the circulating inert gas;inert gas can continuously take away heat on the circulation groove and the heat conduction plate due to liquidity of the inert gas, so that the effect of reducing the temperature of the heat affected zone and the whole device is achieved, a covering layer is formed on the surface of a welding piece after the inert gas is sprayed out of the nozzle, a welding seam can be effectively isolated fromair, and the welding seam is protected against oxidation.