In the deep mining areas of Tonglushan Mine,the stability of the roof has deteriorated,requiring bolt net support in the undercut of the stope.To reduce the exposed area of the working roof,some bottom structures of the stope have been changed from flat bottoms to trench bottoms,and the upward parallel holes have been changed to upward fan-shaped holes.To achieve the best effect of medium-long hole blasting,experimental research on medium-long hole blasting parameters was carried out in the exploration roadway of the deep mining stopes to obtain blasting para-meters such as hole spacing and row spacing applicable to the field conditions.Based on the Livingston blasting funnel theory,a series of tests were conducted,including single-hole tests,variable hole spacing tests in the same section,and inclined step blasting funnel tests.Through the collation of experimental data,the optimal burial depth of the explosive package under the test conditions was determined to be 0.72 m,the hole spacing was 1.6 m,and the minimum resistance line was 0.75 m.According to the blasting similarity law,the actual medium-long hole blasting parameters were determined to be:hole bottom spacing of 2.4 m,and row spacing of 1.1-1.3 m.These parameters were applied to the industrial trial in the mining face of the upper fan-shaped medium-long hole sublevel subsequent filling mining method at -545 m,and good blasting effects were achieved.