The invention discloses a low-grade attapulgite welding rod and a preparing method thereof. A coating of the welding rod comprises, by mass, 35% to 60% of modified low-grade attapulgite, 12% to 23% of dolomite, 15% to 20% of magnesia, 8% to 14% of quartz sand, 1% of starch, 1% of microcrystalline cellulose, 1% to 2% of white mud, 1% to 2% of titanium powder and 1% to 2% of iron powder. The manufacturing method of the welding rod comprises the steps that the welding rod coating is modulated according to the above formula firstly, the welding rod coating and an improved sodium-potassium sodium silicate binder are evenly stirred, a mixture is fed into a welding rod press coating machine to be pressed on a core wire in a coated manner, drying and shaping are carried out, and the welding rod is obtained. The low-grade attapulgite raw ore is subject to modification treatment and serves as the main component of the coating of the welding rod, the waste becomes wealth, the preparing method is simple, the production cost of the welding rod is reduced, the welding rod prepared through the improved sodium-potassium sodium silicate binder is excellent in humidity resistance, the welding technology property is good, and the welding rod has the good application prospect in the welding rod manufacturing field.