Abstract：Based on the method of 3D similitude and numerical simulation，the variety law of aquifer of coal mining above confined aquifer is studied. In most cases，if the distance of coal floor and aquifer is larger than 20 m without tectonic belt，the influence of mining on the aquifer can be ignored. But if the tectonic belt is included，the tectonic belt will be active and the aquifer will connect with the confined water，so water inrush from coal floor may be taken place. The safe distance of mining will be decided with in-situ cases. At the same time，the rationality of the predicting theory of water inrush from coal floor was verified based on the mechanism of water inrush theory with two methods. The conclusions show that in most cases，the confined water is always approaching to the nearest aquifer and than rises to higher aquifer，i.e. the confined water flows from Benxi group aquifer to Taiyuan group aquifer. Finally，water inrush happened. The conclusion indicates that the predicting system is correct and can be used by other similar mines.
