With the rapid development of China's high-speed railway, the output of high-speed trains is also increasing. The outer skin of high-speed trains with a speed of more than 200km/h is almost entirely welded by aluminum alloy plates and large aluminum alloy profiles, so a large number of aluminum alloy welding wires are needed. At present, imported welding wires are mainly used in trains below 300km/h, but with the increase of train speed (above 300km/h), it is necessary to develop welding wires with high strength and better welding performance to ensure the safety of trains. In this paper, 13 alloy welding wires were prepared, and the annealed 5083 aluminum alloy sheet with a welding thickness of 2.8mm was welded by manual AC TIG welding. The microstructure and mechanical properties of welding wire at different stages were studied by metallographic observation, tensile mechanical properties test at room temperature and scanning electron microscope observation. The effects of raw materials, crucible coating, Mg content with different Mn content, Zr content and Mn content with different Fe content on the properties of welding wire were studied, and the following research results were obtained: (1) It is proved that the purity of raw materials has obvious influence on the post-welding properties of welding wire, and improving the purity can make the welding wire obtain better properties. In addition, coating TiO2 on the melting tool can also ensure that the alloy is not polluted during the melting process and that the alloy has high purity. (2) When the content of Mg is changed in the range of 4.5% ~ 5.5%, the mechanical properties of the welded joint of welding wire with 5.5% Mg content are improved, the strength exceeds 90% of the base metal (reaching 287.0MPa), and the elongation reaches 65,438 04.0%. (3) Under the condition of different Mn content, when welding 5083 plate with aluminum alloy welding wire prepared with Zr element, the mechanical properties of the welded joint are higher than those of aluminum alloy welding wire prepared without Zr element. Among them, under the condition of high Mn content, the weld strength of aluminum alloy welding wire prepared with Zr element exceeds 93% (reaching 295.7MPa) and the elongation reaches 16.4%, while the weld strength of aluminum alloy welding wire prepared without Zr element exceeds 90% (reaching 286.0MPa) and the elongation reaches 14.5%. (4) Under the condition of different iron content, when welding 5083 plate with high manganese aluminum alloy welding wire, its welded joint has higher mechanical properties than that with low manganese aluminum alloy welding wire. Among them, under the condition of high Fe content, the welding joint strength of high Mn content aluminum alloy welding wire exceeds 92% (reaching 293.4MPa) and the elongation reaches 15.9%, while the welding joint strength of low Mn content aluminum alloy welding wire exceeds 90% (reaching 285.9MPa) and the elongation reaches 13.8%.

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