The work aims to reduce the surface tension of zinc solution by adding different amounts of Sb element, and to improve the galvanizability and coating quality of X80 pipeline steel. The wettability test was carried out at 450 ℃ by improved sessile-drop method. The contact angle of different Zn-Sb alloy melts on X80 steel substrate was calculated by using Axisymmetric Drop Shape Analysis software (ADSA), the surface tension of the Zn-Sb alloy melt at 450 ℃ was obtained. The results show, when Sb content is 1.0wt.%, the surface tension of Zn-Sb alloy at 450 ℃ is about 0.63 N/m. The surface tension decreases gradually with the increase of Sb content. When Sb content increases to 4.0wt.%, the surface tension reaches 0.46 N/m, which is much lower than that of pure zinc melt. At the same time, the contact angle between Zn-Sb alloy melt and X80 steel gradually decreases from 57° to 43°. A continuous reaction layer composed of iron-zinc compound is formed at the interface between the zinc alloy melt and the X80 steel, and a precursor film exists outside the reaction three-phase line, and the formation of the precursor film causes the subsequent alloy liquid spread on it and promotes wetting. The addition of Sb can effectively reduce the surface tension of zinc liquid and reduce the contact angle between Zn-Sb alloy melt and X80 steel. The surface tension of Sb is low and tends to be concentrated on the surface of zinc alloy. As a surface active element, Sb can reduce the surface tension of zinc liquid and improve wettability.