Abstract:Xingshan Iron Mine is an underground mine, and the high blasting block rate has always affected production efficiency. Combining with the actual production and geological conditions of Xingshan Iron Mine, this paper analyzes the reasons for the formation of large blocks in the process of blasting and falling ore from the aspects of hole layout, filling length, and detonation method. The research results show that accurate analysis of geological conditions and rock structure is very important for the selection of blasting parameters. The parameter optimization of the triangular hole arrangement, the hole filling not less than 400 mm, and the small resistance line and the large hole spacing can effectively reduce the large block rate. According to the field measurement, the row spacing is set to 1.9 m, the side hole angle is 57°, the ore collapse step is 3.8 m, and the average block rate of the stope is reduced by 40%. Shan Iron Mine has a problem of high block rate in engineering practice.