Abstract: The coupling model of the three degrees of freedom in vertical, horizontal and torsional directions for iced quad bundle conductors with rigid spacers is established. The method of transforming the strongly nonlinear system into the weakly nonlinear system is discussed. Simultaneously, by using the average method, the vibration of system is analyzed corresponding to non-internal resonance, 3∶1 internal resonance and 1∶1 internal resonance respectively. Finally, the influence of related parameters such as wind velocity, horizontal damping ratio, fluid density, line span on conductor galloping and the response curves of conductor galloping to the variation of different parameters are obtained. The results show that the approximate analytical solution of system is basically consistent with the numerical solution.