Abstract: The powered emulsified explosive is an advanced and popular explosive which can substitute for ammonium -antimony explosive in our country. The oil phase materials of this advanced explosive mainly consist of paraffin, microcrystalline wax and several kinds of additives, a-mong which the microcrystalline wax has the greatest effect on oil phase materials. Through experimental investigation on the modified formula of microcrystalline, 2# modified rosin and additive 9502 are screened out The laboratory findings indicate that with the combination of 64 # paraffin, 2 # modified rosin and additive 9520, the modification of microcrystalline wax can be realized, which can enhance the dropping point, reduce the viscosity and the penetration of microcrystalline wax The oil phase materials modulated by modified microcrystalline wax is a special - used powered emulsified explosive with high performance which has the characteristics of loose property, easily filling and uneasily blocking screen filter.