Abstract: The research on the law of mine pressure in slurry filling working face aims to solve the problem of resource depletion and succession tension in old mines. It is of great significance to ensure the safe production of mines, optimize mining schemes, improve production efficiency, and promote sustainable development through the slurry filling mining method. The study adopts the method of mine pressure observation to systematically analyze the law of mine pressure display in the working face, the slurry-filled body, the two longitudinal sluice, and the in-situ left and right track, and reveals the change law of key parameters such as the stress change of the filling body and the distance between the roof and the floor through data acquisition and comparison. The study innovatively improved the observation method of the stress of the filling body and the displacement of the top and bottom plates, and improved the accuracy and scientificity of the data. The research conclusion shows that the slurry filling can effectively inhibit the subsidence of the roof, control the movement of the overlying rock, and there is no obvious pressure in the working face, the two longitudinal sluice, and the reserved passage during the reclamation process, which provides a reliable basis for the selection of support parameters and equipment. In addition, the research also provides data support for the stratified filling mining of thick coal seams, which is of great significance for optimizing the mining plan and reducing production costs.