In view of the application situation and problems of mixed emulsion explosive in the cold and high-altitude area,especially the short storage period of the mixed emulsion matrix,easy crusting on the surface,high storage safety risks,poor on-site sensitization quality,too many invalid large bubbles,the state of "tofu dregs",and so on.In order to solve the problems above,the water-phase and oil-phase formula design and field sensitization are optimized,which reduces the number of major hazard sources in the mining area,improves the intrinsic safety of the matrix,improves the storage stability of the matrix and the sensitization effect of explosives.At the same time,it will not have a negative impact on the current production process,explosive performance and blasting effect of mixed emulsion explosives.These improvements can effectively solve the technical problems in the production and application of mixed emulsion explosives in cold and high altitude environment.The results show that when the water content of emulsion matrix increases from 14% to 17%,the natural storage period of emulsion matrix increases from 25 days to 40 days,and the detonation velocity is measured as 3900~4000 m/s which is at a comparable level with the test result of 3700~4200 m/s before any adjustment.The field tests indicate that the blasting effect has meet the demands.By adjusting the content of citric acid and introducing foaming promoter E in the water formula,the density of the explosive is finally controlled as 1.15~1.20 g/cm3.In addition,the field sensitizing quality of the explosive has been improved obviously.The natural storage time of the emulsion matrix is significantly increased from 45 days to 70 days by using the polymer emulsifier EPE-3021.