Abstract: The damage mechanism of rock under transient energy caused by blasting is the research focus of blasting and underground space engineering. The research conducted field blasting experiments,and ultrasonic wave velocity,porosity,resistivity,and tensile strength tests as well as scanning electron microscope(SEM)inspections of rocks after blasting were carried out. By comparing them to rocks not affected by blasting,the blasting damage characteristics and range of rocks were identified. Then,the damage variables based on the change of macro porosity and micro-crack density were established,and the damage mechanism of the samples was analyzed qualitatively and quantitatively. The results show that the degree of change in the macroscopic test indicators of the altered diorite porphyrite at BZ2,BZ3,and BZ4 decreases continuously with increasing depth,presenting distinct characteristics of consistent stepwise change. The sequence of variation degree is BZ2,BZ3,and BZ4. Based on the change of the macro indicators,it is comprehensively analyzed that the damage depths of the rocks at BZ2,BZ3,and BZ4 are 5.72 m,3.71 m,and 2.85 m,respectively. The underlying cause of the difference in rock damage degree is the differential change in the development degree and connectivity of micro-defects such as cracks and pores due to blasting. There is a significant quantitative linear correlation between macro and micro damage variables and macro damage characteristics. Therefore,they can be used as quantitative indices to reveal the range and degree of rock damage caused by blasting.