In order to improve the weld forming effect and reduce the welding cost, most modern factories use the mixed gas welding process, so the gas mixer has become an indispensable production equipment for the factory. Through the internal precision configuration device, the gas mixer can effectively promote the uniform mixing of gases, and produce high-precision uniform gas mixtures according to the requirements of use for subsequent use. By using mixed gas, the welding speed of workers can be increased by more than 40%, effectively reducing the cost of labor and gas, and at the same time the weld is better formed, smooth and bubble-free, without manual secondary grinding. It not only improves the accuracy of welding quality, but also further reduces costs, and the improvement of production efficiency is very obvious. Gas mixer is a large-flow binary or multi-gas mixing device designed for laser cutting and welding, mainly used for centralized gas supply busbars, two or more gases to be mixed according to the requirements of use, and obtain a uniform gas mixture. It can be widely used in laser cutting, gas welding protection, railway, shipbuilding, chemical, machinery manufacturing and other gas shielded welding occasions.