During the promotion test of 310 mm blasthole blasting at a large open⁃pit mine, issues such asover⁃fragmentation at the bench toe and insufficient breakage in the upper part of the bench were observed. Consideringthat the propagation velocity of stress waves in rock mass and the blasting wave velocity of explosives are of the same orderof magnitude, numerical simulations were conducted to investigate the influence of different detonation point locationswithin the blast hole on stress wave propagation. The analysis showed that bottom detonation produced the higheststress wave peak in the upper bench with the shortest duration, while top detonation（at the hole collar）produced thehighest peak in the lower bench, also with the shortest duration. In⁃hole detonation resulted in intermediate stress wavepeaks and durations in both upper and lower sections, with the stress wave peak occurring in the middle part of thebench. Based on a comprehensive assessment of stress wave peak values and load duration, field trials were carried outby lifting the first detonator charge to a position between the hole bottom and middle（0.5-4.5 m above the holebottom）. This significantly improved fragmentation in the upper bench and validated the simulation results.