The ice galloping of overhead conductors is an essential factor leading to line trips, which seriously threatens the safety and stability of power system operation. How to calculate the tripping probability of the ice galloping of overhead conductors scientifically and rationally according to meteorological information has become an urgent problem to be solved. To calculate the short-circuit tripping probability of transmission line caused by galloping under the freezing weather, the information of wind speed, frozen rainfall, temperature, and humidity in the freezing weather area were first collected. Weibull distribution was used to fit the probability density distribution function of the wind speed and calculate the icing thickness of the conductor. Secondly, based on Newton's method, the single-degree-of-freedom galloping model of iced conductors was built. The Ritz-Galerkinn method was used to obtain the analytical expression of amplitude. The probability distribution function of the over-limit of galloping amplitude was obtained by combining the probability distribution of wind speed and the icing thickness. Then, the tripping probability is obtained by analyzing the phase relation of the three-phase conductor during the non-synchronous galloping. Finally, the Monte Carlo method is used to simulate the process of galloping tripping of an iced conductor, and the statistical value of galloping over-limit tripping probability is obtained. The results of an example show that the method can accurately calculate the probability of galloping tripping from the meteorological information obtained from the weather forecast.