Abstract: Rockburst is a typical brittle dynamic failure that is accompanied by huge elastic energy releasing during the construction of deep tunnels,resulting in severe economic losses,casualties,and delays in project schedules. Therefore,gaining a thorough understanding of the mechanism behind rockburst formation is crucial for the successful implementation of tunneling projects. In this regard,a calculation method to enhance the discriminant index x Q_gMC of the Mohr-Coulomb strength criterion(GM-C) and the discriminant index Q_gDP of the Drucker-Prager strength criterion(GD-P)by considering the rock integrity coefficient K_v and coefficient of weathering K_f was proposed. Additionally,the formation,extension,merging,and agglomeration of microcracks from a micro to macro perspective was analyzed,using Griffith's criterion. Furthermore,formulas for the rock cohesion c and the angle of internal friction φ were established,taking into account the damage factor D. To evaluate the propensity for rockburst,the rockburst propensity index P,considering the influence of the surrounding rock grade,was introduced. A comprehensive method for determining the strain rockburst grade by considering both the strength criterion and energy theory was proposed. To validate the proposed rockburst grade judgment method,rockburst state data from twelve typical projects in China at various points were selected. The results demonstrate the feasibility of calculating the discriminant index Q of the rock strength criterion to determine rock yield damage,followed by calculating the indicator of rockburst propensity P to determine the grade of rockburst. This method provides site staff involved in tunnel construction with a novel approach to accurately and timely judge the grade of rockburst,incorporating a comprehensive consideration of the strength criterion and energy theory.