Transmission line galloping disasters will cause serious power grid safety accidents and economic losses. In order to warn the occurrence of galloping accidents, a graded warning scheme of transmission line galloping based on grey clustering analysis was proposed. According to the main reason of the galloping, an indicator quantity system affecting the transmission line galloping was established from three aspects: meteorological factors, wind incentives and line structure factors, and AHP was used to calculate the weight of indicators. A graded warning scheme was designed by using grey clustering analysis. The comprehensive clustering coefficient was calculated from the whitening weight function and the weight value, and the maximum value was used to judge the galloping state. The calculation results of examples agreed well with the actual galloping state. The graded warning scheme of this paper could provide reference for the prevention and control of galloping accidents.