With the gradual increase of coal mine construction and production scale, the amount of dust generated from coal mines increasing, which seriously affected the health and safety of workers. In this paper, COMSOL Multiphysics was used to conduct three-dimensional numerical simulation to analyze the dust diffusion process and related factors affecting dust concentration distribution were studied to investigate the numerical simulation of the effects of changes in airflow parameters, belt operation status and coal transportation volume on dust, transportation and diffusion patterns. The results showed that the dust dispersion velocity and range were greatly influenced by the wind speed and the viscosity of the wind flow, a larger wind speed or a lower viscosity would lead to increased dust pollution.