Abstract: Applying the theory of system and associating many ways to study the deformation of slope,the paper sets up an engineering geology system to examine the deformation and failure of slope.The system consists of three subsystems used respectively to calculate the stability based on artificial neural network,to evaluate the reliability and to predict the deformation of slope founded on gray system theory,so it can fulfill those functions.The results of actual application indict that the system's applicability is good,and it can provide the necessary reference to bring slope hazard under control.