A low-alloy steel flux-cored welding wire for carbon dioxide gas shielded welding, the composition and content of the flux core in % of the total weight of the welding wire are as follows: TiO2: 3-6, Si: 0.3-0.5, Mn: 1.5-3.2, SiO2: 0.1 -0.8, ZrO2: 0.1-0.5, Fe: 2-7, Al+Mg: 0.5-1.2, Ni: 0.5-5, B: 0.002-0.015, Ti: 0.1-0.3, oxidation of alkali metal K, Na, Li The content of fluoride or fluoride equivalent to K, Na, and Li is 0.1-0.35, the content of fluoride F is 0.05-0.2, the fluoride or oxide of rare earth metal is equivalent to 0.005-0.2 of rare earth metal, and the content of C, Si, and Mn in the welding wire The product of the contents is 0.058-0.11. For high-strength low-alloy steel all-position welding process performance is good, it can maintain good arc stability and welding operation performance under the condition of high current and fast welding, the weld seam is smooth, the connection strength is high and it has a good -40 ℃ low temperature Impact toughness and excellent crack resistance.