Abstract: According to one of the performance parameters of underground emulsion matrix and sensitizer of metal underground mines，the fluent software is used to make numerical simulation on the mixed and sensitized effect of underground site emulsion explosive through the impinging stream mixing unit. The mixing effect under different structure parameters of the V type impinging stream mixer is simulated through orthogonal tests. The simulation results show that the V type impinging stream unit with 4 entrances，5 mm of diameter，90° entrance angle and 10 mm outlet diameter is the best. It can achieve the requirements of short distance continuous static mixing sensitization for underground site mixed emulsion explosives.

Key words: Underground mining, Numerical simulation, Impinging stream, Emulsion explosive