Abstract: It is of great significance to study the main control factors of erosion and water inrush from the confined water guiding column of coal mine floor to reveal the water inrush mechanism of the Karst collapse column and to guide its water inrush prevention. The mechanical model of erosion and water inrush of collapse column is established, the multi-physics coupling software COMSOL Multiphysics is used to numeralize the model. The non-uniform distribution characteristics of the cracks in the collapse column are considered to perform the simulation research for the whole process of water inrush of collapse column under erosion action, and the influence of water pressure, initial fracture distribution and fracture development degree on water inrush of collapse column are analyzed. The results show that the greater the aquifer water pressure and the initial fissure opening is, the faster the water inflow from the collapse column increases and the greater the risk of water inrush is. The initial fracture distribution mainly affects the distribution of the final water inrush channel, and has little effect on the water inrush time and water inflow. Under the action of hydraulic erosion of confined aquifer, the filling particles in the collapse column liquefy and migrate away, and some cracks continue to increase and penetrate and develop into several superior water guiding channels, which ultimately causes the sudden increase of water inflow in collapse column and the occurrence of water inrush accidents.