The invention relates to a conductor galloping instability analysis method. The method comprises the steps of (1) determining pneumatic parameters and a pneumatic load according to an eccentric icing form of a conductor; (2) building a conductor galloping oscillation starting wind speed calculation model for calculating a conductor galloping oscillation starting wind speed according to the pneumatic parameters and an oscillator model; and (3) calculating a conductor galloping amplitude characteristic according to the pneumatic parameters and the conductor galloping oscillation starting wind speed calculation model. The technical scheme has a very important effect for improving the accuracy and effectiveness of anti-galloping design of a power transmission line.