Abstract: In underground mining operation, toxic and harmful gas pollutants will be produced in the process of explosion, which is very harmful to human body. In order to explore the migration law of toxic and harmful gas pollutants concentration and the time required for gas concentration to fall to the safe limit, ventilation simulation software Ventsim, data processing platform SPSSPRO, regression prediction analysis method and grey prediction model are used to simulate and analyze the migration of dangerous toxic and harmful gases produced after blasting in underground mine. The results show that the pollutant concentration curves can be divided into rising zone, falling zone and slow falling zone. After data fitting, it is concluded that the pollutant concentration variation in the declining area follows exponential distribution, and the specific concentration attenuation formula is obtained. After the prediction and analysis of grey model and SPSSPRO platform, the prediction equation of grey model is obtained. It is concluded that the time required for mine to fall to the safe limit concentration is 65 min, which provides a theoretical basis for the time required for mine workers to re-enter the working face after blasting.