In order to reduce the harm of dust dispersion in open-pit coal mine to the mining environment and the damage of personnel and equipment, this paper carried out the research on dust migration, distribution and treatment in open-pit coal mine by taking Hequ open-pit coal mine as the engineering background.The results show that: ①by means of on-site monitoring, this study analyzes the changes of dust concentration in different areas, and further determines the main dust producing areas of open-pit coal mine; ②The fractal dimension is introduced into the migration and distribution of dust, and the relationship between dust particle size, wind speed and fractal dimension is studied; ③A clean, efficient and low-cost chemical dust inhibitor was developed by studying the ratio of chemical dust inhibitor based on polymer materials.The chemical dust inhibitor has a good capture effect on dust particles and can form a film after spraying to prevent secondary dust.