Abstract: The conditions of coal rocks and the excavation speed and the geometric parameters of the tunnel have a significant effect on the negative-pressure dust removal performance of the application of dust removal fan in tunnel with harsh environmental impact. This paper carries out the numerical simulation of the two-phase flow field of the negative-pressure dust removal under the conditions of the typical tunnel geological conditions using the Fluent software. The Lagrangian method based on the Discrete Phase Model （DPM） is used for three-dimensional unsteady numerical simulation. The Realizablek-ε turbulence model is used for numerical calculation. The SIMPLE algorithm is used for the coupling of velocity and pressure. The pressure discretization is based on the standard format, and the rest is based on the second-order upwind scheme. The effects of coal rock parameters （the density and particle size of the coal powder）, the speed of the excavation （the mass flow rate of the coal） on the dust migration characteristics and negative-pressure dust removal performance in the tunnel are numerically investigated. The results indicate that the density of coal powder has a slight effect on dust removal performance, and the dust removal efficiency only decreases slightly with an increase in density of coal powder. Besides, as the average particle size of pulverized coal increases, the dust concentration in tunnel increases, and the dust removal efficiency decreases. In addition, the variation in mass flow rate of coal powder studied here has slight effect on the efficiency of dust removal, but the concentration of space dust increases with an increase in mass flow rate of coal powder, which causes a harmful effect. Finally, through on-site dust concentration testing experiments, the influence of coal and rock conditions and excavation speed on negative-pressure dust removal efficiency is explored. The experimental results indicate that excavation speed and coal particle size can reduce the dust removal efficiency of the negative-pressure device, while the influence of the change in the density of the coal powder on the dust concentration in the tunnel and the efficiency of negative-pressure dust removal can be basically ignored. Based on the above results, the following suggestions can be put forward for tunnels with different coal rock conditions: if the tunneling speed increases or the size of the coal powder particles becomes larger, it is recommended to adopt measures such as simultaneously increasing the power of the air compressor and the dust removal fan; if only the density of the coal powder changes, the dust removal strategy and methods can remain unchanged.