Abstract: The aerodynamic coefficients of the iced quad bundle conductor and a single conductor are obtained under four different conditions through wind tunnel test. The equivalent aerodynamic coefficients of the central axis of the quad bundle conductor are obtained by the equivalent method and compared with those of a single conductor under the same conditions. Based on the Den Hartog's galloping mechanism and the Nigol's torsional mechanism, the stable and unstable regions of the equivalent coefficients of the iced quad bundle conductor are determined. The results of this paper can be used in the research of the galloping and the simulation of the galloping of the iced conductor.