The invention discloses an environment-friendly carbon-gold battery horizontal terminal cast welding method. The environment-friendly carbon-gold battery horizontal terminal cast welding method comprises the following steps that A, preparation before welding is carried out; B, temporary spot welding is carried out; C, the welding is carried out; D, post-welding treatment is carried out; E, protective paint is sprayed; and F, packaging is carried out after passing inspection. The preparation before the welding includes the following steps that (1), accumulated water and accumulated snow on thebattery shell surface are removed completely to ensure dryness of the battery shell surface; (2), dirt of blocked rust oxide, greasy dirt, and the like on the surface of an horizontal terminal is cleaned up; and (3), a welding mode and a welding material are selected, Tungsten inert gas arc welding (TIG) is adopted, the type of the welding material is an ER CuNi-7 welding wire with phi 3.0mm, thewelding current is 250-300A, the welding voltage is 20-24V. According to the environment-friendly carbon-gold battery horizontal terminal cast welding method, a welding technology is adopted, the occurring of the phenomena of leakage welding, multi-welding, incomplete cleaning of welding slag and unqualified welding seams can be effectively avoided, the welding efficiency of the horizontal terminal is improved, the welding quality is ensured at the same time, and the environment-friendly carbon-gold battery horizontal terminal cast welding method is in line with self interests of enterprises.