Abstract: To address the issue that shallow-hole blasting technology fails to effectively precrack the deep rock mass and has poor precracking effect on the rock mass in the sealed hole section when there is a hard fault in the fully mechanized mining face，resulting in slow advancement speed of the fully mecha⁃ nized mining face and high wear of the shearer's cutting teeth，this study takes the F19 fault in the 2-801 fully mechanized mining face of Liyazhuang Coal Mine as the research background. By means of theoretical analysis，on-site investigation and measured analysis，the principles of blasting technology，hole depth， hole diameter，spacing between blast holes and charge parameters were studied and analyzed to investigate the influence of different hole depths on the effect of precracking blasting. It is determined to adopt a com⁃ bined approach of medium-deep hole blasting technology and deep hole blasting technology. By using deep hole blasting to precrack the rock mass within a large area of the deep part of the fault，and then conduct⁃ ing medium-deep hole blasting on the rock mass at the deep hole blasting hole blocking section，the shal⁃ low rock mass can be loosening，allowing the rock mass fractures at the fault layer to develop throughout the range. With the assistance of a coal shearer in cutting the rock，the fully mechanized mining face can efficiently pass through the fault zone. The results show that through two blasting operations，the medium�deep hole precracking technology greatly reduces the strength of the rock mass，making it easier for the shearer to cut the rock mass. Through recorded observations，the average daily advancement speed of the fully mechanized mining face when passing through faults has increased by 48%，and the average wear of the shearer's cutting teeth has decreased by 51%. By medium-deep holes precracking blasting technology，
the strength of hard fault rock masses can be effectively reduced，production costs can be saved，and pro⁃
duction efficiency can be improved.

Key words: medium-deep hole blasting, blasting precracking, hole layout, crossing fault