With the high risk of coal and gas outbursts in deep roadway tunneling, gas extraction from the floor rock roadway is an effective way to reduce coal seam gas pressure and protect the safety of coal roadway tunneling. The location of the rock roadway and its effect on the coal roadway is a problem worth studying. In this work, taking the Shoushan No.1 mine as the engineering background, a corresponding discrete element model is established based on the rock stratum. According to the sequence of roadway excavation, the changes in rock stress, rock deformation and the damage distribution are analyzed. Results show the floor rock roadway has a certain unloading effect on the upper coal seam, and this effect is reduced when the distance between the rock roadway and the coal roadway increases. The deformation of floor rock roadway increases significantly after the coal roadway tunneling. The damage of the floor rock roadway is mainly affected by the roadway position, and the soft or thin rock layers are not conducive to roadway stability. The vertical distance between the coal roadway and the rock roadway is finally determined as 12m and the field investigation results show the floor rock roadway and coal roadway have good stability.