Abstract: In recent years,separation strata water-inrush had gradually become a major type of water hazard.that made the mechanism of separation strata water-inrush become a hot and difficult topic to be tackled.In order to clarify the process of separation strata water-inrush,the mechanism of separation strata water-inrush was to be a critical issue to study.Based on catastrophe theory,structural mechanics and material mechanics,this paper established a mechanical model of the key strata (overburden rock beam structure of the separation strata) through dynamics analysis.Based on the energy,the expression of the total potential energy function of the key strata was obtained.On the premise of mechanical equilibrium,the sharp point mutation model of the key strata breaking expressed by energy was constructed,and the impact energy released after the key strata breaking was calculated,the "fracturing" modes and "cleavage" modes of “separation strata water-inrush” were proposed under the impact energy of the key strata,the location of two kinds of water-inrush modes was predicted.Finally,on the basis of fully analyzing the geological and hydro geological condition,separation strata water-inrush of the 3 coal seam of Guojiahe Coal Mine was taken as an example to apply study,by means of field measurement,laboratory test and theoretical analysis.The study results show that:the key strata abrupt breaking was a kind of energy jump mode,which can be explained by the sharp point mutation mode; The "fracturing" modes and "cleavage" modes of “separation strata water-inrush” proposed can predict the water-inrush position; The predicted position of separation strata water-inrush from the working face was basically consistent。