Field detection of surrounding rock damage range is cumbersome.In order to obtain the surrounding rock damage range simply and accurately,a major underground cavern project to be built is taken as the research background.Theoretical analysis and numerical simulation are adopted according to the blasting design scheme to establish the cumulative damage calculation model of multistage delay blasting with different charges.By using equivalent blasting load method and LSDYNA complete restart technology,the blasting vibration data and the cumulative damage range of surrounding rock under multistage delay blasting loads are obtained.The cumulative damage effect of surrounding rock of the underground cavern is analyzed and the correlation between blasting vibrations and the cumulative damage range of surrounding rock is studied.The results show that the induced damage of surrounding rock of the underground cavern is mainly caused by blasting of the second circle holes and the surrounding hole,and the damage range of surrounding rock of the cavern vault(2.21 m) is significantly larger than that of the surrounding rock of the arch waist(2.05 m).The peak value of the blasting vibration curve is within the delay time range of cutting holes,which is not consistent with the blasting stage that causes the damage of surrounding rock.Therefore,the correlation between the peak particle vibration velocity and the damage range of the surrounding rock should be studied within the delay time which has great influence on the damage of surrounding rock.The quantitative relationship between the cumulative damage range of surrounding rock and blasting charge,blasting center distance and peak particle vibration velocity is established,and the functional relationship between the cumulative damage range of surrounding rock can be deduced from the peak particle vibration velocity at any blasting center distance.It provides a basis for controlling the blasting damage of surrounding rock and has practical significance for guiding the safety of blasting construction on site.