Abstract: In order to study the influencing factors of coal dust settlement effect and quantitatively express the relationship between the factors, based on the industrial analysis of coal sample, surface tension experiment and settlement experiment, the parameters are selected and the quantitative model is established. The multiple regression and path analysis method are used to improve and optimize the quantitative model of settlement effect. The results show that the settling effect of coal dust is mainly related to ash content, fixed carbon content, particle size, surfactant molecular weight, concentration and surface tension of surfactant, and the concentration of surfactant solution and particle size of coal dust have more significant effects on settlement effect; the higher the content of coal ash and volatile matter and the molecular weight of surfactant, the lower the concentration and surface tension of surfactant and the fixed carbon content of coal, the better the settlement effect of coal dust; the quantitative model of settlement effect can be used to predict the experimental results of medium rank coal dust settlement.