In open-pit bench blasting,blasting TBlasting toe rocks is an important indicator to measure the blasting effect in open-pit bench blasting,and it is most directly influenced by the blasting parameters have the most direct influence on the formation of blasting toes.In order to find outresearch the influence of ultra-deepsubdrilling on the smoothness flatness of bench in deep-hole bench blasting,statistical analysis of the relationship between damage variables and wave velocity in rock mass was conducted based on the basic theories of rock damage mechanics.based on the basic theories of rock damage mechanics and through statistical analysis of the relationship between damage variables in engineering and wave velocity in rocks,Tthe threshold values of damage variable,Dd for critical damage variable damage state of of rock mass is determined as Dd that is was 0.2,and the damage threshold Dt of for rock breaking mass in critical broken state is was were defined as 0.2 and 0.8,respectively .based on the basic theories of rock damage mechanics and through statistical analysis of the relationship between damage variables in engineering and wave velocity in rocks.Furthermore,Based on the dynamic damage model of rock with comprehensive consideration of the damage effect of tension and compression,the damage range of bench blasting under different conditions of with different subdrilling conditionsultra-deep was simulated by using the dynamic finite element analysis program LS-DYNA based on the dynamic damage model of rock mass with a comprehensive consideration of tension and compression effect.Meanwhile;based on the threshold of critical damage variable,the fluctuations distribution image of the bench surface after blasting was drawn to determine the optimal ultra-deep of subdrilling hole based on Dt the threshold of critical damage variable,and the image is was used for the quantitative analysis,so as to ensure that the rock mass of upper bench was fully damaged without affecting the construction of the lower bench surface.Finally,combined with the actual situation of deep-hole bench blasting in Ezhou Airport,the influence mechanism of ultra-deepsubdrilling on blasting toes is was verified in the deep-hole bench blasting of Ezhou Airport,and an optimal method for determining the optimal ultra-deepsubdrilling value for deep-hole bench blasting is was concluded.