Abstract:Rock burst is a kind of catastrophe during the excavation in underground projects. It is a process of energy release and rock block casting. So the energy change in the surrounding rocks of underground projects must be analyzed. The elastic strain energy of rocks before excavation,energy release and gathering in surrounding rocks,the condition of energy transfer,and the energy variation of rocks in front of cutting face are studied. When the strain energy reaches its limit energy storage in one point,the surplus energy will be released and produce plastic deformation,or rock fracture,and the remaining energy will shift into the deeper part of the rock. If the energy is especially large and can not shift into the depths,the rock burst will take place. This theory has been successfully used to prevent rock burst.