In the mining process of coal mines, with the end of mining of various working faces, there are residual island coal pillars in the mining area, and many old-fashioned roadways in the coal pillars. With complex surrounding rock stress of these roadways and the destroyed stability of surrounding rock, especially in the process of mining in the old roadway parallel to the cutting eye, it is easy to cause the roof collapse and crush the bracket, which seriously restricts the safe production of the mine. Through the application of FLAC3D software, the variation law of the surrounding rock of the roof in the fully mechanized caving face was simulated and filled, and the comparative analysis was carried out. The ultra-high water material filling empty road scheme was proposed and applied to the 30106 fully mechanized caving working face. The mining practice showed that the effect of filling the empty road with super high water material was significant, which provided a reference for other similar coal pillar working face filling and filling.