Abstract:The equations of bending moment and deflection line of rock beam in dissymmetric mining are deduced. Using the symbolic operation software Maple9.5,the catastrophe model of dynamic buckling in rock beam—pillar system,is established through the way that the differential form of total potential function is deduced by principle of conservation of energy. The critical condition,positions of start point and end point of pillar destabilization are analyzed,and the elastic energy releasing amount of rock beam at destabilization instant is also given. The diagrammatic form of the behavior of pillar destabilization,which is protracted by the software Matlab,contains rich information. It has important effect on the problem of realizing the behavior rule in every deformation phase of rock beam—pillar system,and it distinguishes the equivalent stiffness of rock beam in a certain direction. The analytical results show that the equivalent stiffness of rock beam is the largest in symmetric mining,and that dissymmetric mining lessens the equivalent stiffness of rock beam. The pillar surfers eccentric compression in dissymmetric mining,so it lessens the stiffness of pillar,i.e. impact tendency. The resultant effect shows that the destabilization intensity of pillar is smaller than that of symmetric mining.