Abstract: Modern earth fissure appears in almost every country recently and it has been a main kind of geo hazard up to the present day.Based on the coupling technolgy of GIS & ANN,this article has developed the nonlinear simulation and assessment system of earth fissure.On the basis of analyzing the causes of earth fissures,this article setups four geo information layers (such as structure,groundwater mining,stratum and physiognomy) with the spatial analyzing function of GIS.And this article setups the nonlinear simulation and assessment model of earth fissure with ANN,the engineering technology of simulating the neural net of mankind.And with this assessment system,this article evaluates the fatalness of earth fissure in Yuci,Shanxi,plots the fatal grade according to fatalness coefficient,and provides the scientific basis for the decision making of city construction,environmental protection and land programming in Yuci City.