Abstract: In order to find out the role of mining in the failure and water inrush of the surrounding rock of karst collapse column of the working face floor, taking the hidden karst collapse column of the floor of Geting Coal Mine as the research object, FLAC^3D numerical simulation software was used to analyze and study the vertical stress field, plastic failure zone and vertical displacement changes in the mining process. The water inrush process of karst collapse column of hidden floor with different advancing distance is analyzed. The research results show that with the increasing of the advancing distance, the plastic failure range of karst collapse column is increasing, and the vertical displacement of the floor is increasing. When the plastic failure area of the coal seam floor is connected with the plastic failure area of the karst collapse column, water inrush accident of the karst collapse column of the floor is likely to occur.