Abstract: In view of the problem that the unit consumption of explosives increased in the later stage of mining in Waitoushan Iron Mine，the comprehensive improvement of blasting technology is carried out. The three-dimensional blasting control technology system is constructed. The top air interval charge struc‐ ture is adopted in the vertical dimension，the parameters of the equilateral triangle hole network are opti‐ mized in the horizontal dimension，and the dynamic ultra-deep design adjustment is carried out in the depth dimension. At the same time，the porous ammonium oil explosive is optimized，and the closed-loop control mechanism of construction quality is established to form a collaborative control mode of“geological adaptation-parameter optimization-process control”. The field application results show that the unit con‐ sumption of explosives after technical improvement is reduced to 3 297.2 kg/10 000 t，which is 4.12% low‐ er than that before optimization，and the direct economic benefit is 1.944 million yuan per year. The blast‐ ing effect is significantly improved and the comprehensive cost is effectively reduced. The coordinated con‐ trol mode provides a systematic scheme for the optimization of blasting parameters in the later stage of deep open-pit mining，and has good promotion value.

Key words: open-pit mines, unit explosive consumption, air interval charge, optimization of blasting parameters