Abstract: Metal fittings are an important component of overhead transmission lines, and the special operating environment puts higher requirements on the mechanical properties and high temperature resistance of metal fittings. Therefore, the application research of high-strength aluminum alloy metal fittings in overhead transmission lines is proposed. Based on the characteristics and material selection principles of metal fittings in overhead transmission lines, aluminum clad Invar core heat-resistant aluminum alloy gold is selected as the metal fitting material. Based on the commonly used "composite insulator single hanging point single connection Ⅰ-type suspension string" in overhead transmission line engineering, the metal fitting structure is designed through theoretical calculations and processed into high-strength aluminum alloy metal fittings. Taking a certain power project as the background, high-strength aluminum alloy fittings are applied to connect overhead transmission lines. Through performance testing, the failure load of high-strength aluminum alloy fittings is above 190 kN, which has good bearing performance; high-strength aluminum alloy fittings can withstand high temperatures above 180 ℃ and have good high-temperature resistance, which can meet the high-intensity operation requirements of overhead transmission lines.