Wind speed, temperature, air liquid water content, and median volume diameter of water droplets are the main environmental parameters influencing conductor icing. This paper establishes a “four-parameter” model for wire icing using principles from fluid mechanics and thermal equilibrium considering the motion, collision, and freezing processes of water droplets. Through numerical computations, the study analyzes the unique impacts of each environmental parameter on the growth rate of conductor icing. Additionally, empirical formulas for liquid water content and median volume diameter of water droplets are developed based on practical line monitoring data. Subsequently, a predictive model for conductor icing is devised, relying on readily obtainable sensor data. Research findings reveal that the influence of the median volume diameter of water droplets on the rate of conductor icing exhibits a saturation characteristic, while variations in air liquid water content correlate with wind speed, temperature, and humidity. These conclusions provide a theoretical foundation for predicting and early warning systems for icing on transmission lines.