To capture the characteristics of faults accurately, considering a typical coal mine as an example, the geological model of fault zone and fault plane is established by the numerical calculation method, and the influence of thickness of fault fracture zone and fault plane on mining of coal mine working face under normal fault condition is studied. The study shows that the smaller the stiffness of the fault plane is, the more time steps need to be calculated for the model balance. Under given conditions for the thickness of the fault zone, the influence of the fault plane gradually increases as the working face advances closer to the fault plane under the conditions of different contact surface stiffness, the stress peak in front of the working face tends to rise with the increase of interface parameters, and the stress peak is the highest when there is no interface, and the vertical displacement of the working face roof increases gradually with the decrease of the interface stiffness. The stress in front of the working face increases with the increase of the thickness of the fault zone under the same interface parameters. The vertical displacement of the roof increases with the thickness of the fault zone. With the increase of the vertical distance from coal seam under different interface parameters, the displacement difference between the two sides of the fault of the high strata is larger than that of the low strata, and the two separate plates is also larger in the high strata. Under the condition of different fault zone thicknesses, the displacement difference between the two sides of the fault increases with the advance of working face. The slip amount of the point with higher strata is larger than that of the point with lower strata in a certain range of vertical distance. The slip amount on the two sides of the fault increases with the increase of the thickness of fault. This study has certain guiding function for coal mining under the influence of faults.