Abstract: In order to study the catastrophe mechanism of floor water inrush under the action of dynamic disturbance, a test system of roadway water inrush and mud inrush which can apply dynamic disturbance was designed, and the similar simulation tests of floor water inrush with different disturbance frequency and amplitude were carried out. The test results show that the floor water inrush is the result of the combined action of excavation disturbance, dynamic disturbance and confined water seepage. The precursory characteristics of water inrush are the decrease of soil pressure, the sharp rise of water pressure and the large number of acoustic emission events. With the increase of disturbance amplitude and frequency, the water inrush pressure decreases, the soil pressure increases during water inrush, and the water inrush time advances. The three are more sensitive to the disturbance amplitude. Based on Hoek-Brown strength failure criterion, the P-M critical equation of floor water inrush point under dynamic disturbance is established by introducing rock mass disturbance coefficient. The comprehensive accuracy of this equation is 87.6 % in the prediction and evaluation of mine floor water inrush risk, and the applicability is good. Through the prediction of the drilling results of Tangjiahui Mine by the P-M critical curve under dynamic disturbance, it is found that the P-M results of some boreholes in the southern part of the mine are higher than the critical curve. Combined with the actual situation of the mining area, it is determined that the safety degree of the northern part of the mine is the highest, the middle part ( the main mining area ) is lower, and the risk of water inrush in the south and southwest is the highest. The research results provide theoretical guidance for the prediction and prevention of water inrush from roadway floor, which is of great significance to ensure the safe production of coal mine.