Under the background of the "New Infrastructure" the expanding construction of power lines has once again highlighted the threat of conductor icing to the safe and stable transmission of electricity. Timely and accurate simulation and prediction of conductor icing are of great significance for the grid's anti-icing and disaster mitigation efforts. The currently widely used conductor icing models primarily rely on four environmental parameters: median volume diameter (MVD) of water droplets, liquid water content, wind speed, and ambient temperature, with less consideration given to the droplet size distribution characteristics. This paper uses the Langmuir droplet size distribution spectrum as a template to establish finite element and analytical models to simulate the collision characteristics of water droplets on the conductors. It compares and analyzes the differences in the water droplet collision coefficient α1 calculated using the droplet size distribution spectrum and the median volume diameter. The concept of the characteristic median volume diameter dx of water droplets is proposed. The research results show that, compared to the finite element method, the analytical method has significant advantages in terms of convenience and calculation speed, although it has a calculation error of around 0.1. The error Δα1 between the α1 calculated using the MVD and that using the droplet size spectrum depends on the distance between MVD and dx; when MVD is close to dx, Δα1 is small, and vice versa. The findings of this paper can provide a technical reference for the reasonable selection of droplet size parameters in conductor icing simulations.