Abstract: In the trenching blasting operations of large deep open-pit mines，to address the common problems such as insufficient looseness of the blasting piles，significant post-blast erosion，and higher blasting vibration intensity compared to other operation areas，based on the actual blasting cases of Nanfen Open-pit Mine and Limestone Mine，the blasting technology was innovatively applied by focusing on the optimization of the blasting parameters and the blasting method.In the selection of the blasting method， the applicable scenarios of vertical blast holes and inclined blast holes were compared and analyzed，and on this basis，three core technical means were adopted to improve the effect.First，the upper free surface was fully utilized to guide the blasting energy to be released in the predetermined direction，reducing inef⁃ fective impacts.Second the delay time，was reasonably controled，and adopted the millisecond delay initia ⁃ tion technology to make adjacent blast holes ignite successively，reducing mutual interference and improv ⁃ ing the dispersion degree of the blasting pile.Third，strictly controled the amount of explosives detonated simultaneously，was the single-stage detonation amount within the safety threshold was bept，reducing the blasting vibration intensity from the source.The application results show that the implementation of this technology has brought significant benefits，increasing the bucketing efficiency by approximately 30%，re⁃ ducing the post-blast erosion distance from 8 ~10 m to 2 ~5 m，achieving a dispersion degree of 1.4 ~1.5， reducing the blasting vibration intensity by more than 30%，effectively protecting the stability of the sur⁃ rounding slopes，significantly reducing the impact on important buildings and residential areas around， creating considerable economic benefits，and providing strong support for the safe and efficient mining of large deep and deep-cut open-pit mines.

Key words: large deep open-pit mines, ditching blasting, vertical holes, inclined holes