Advantages of resin microspheres sensitization and other physical sensitization methods of emulsion explosive were compared and analyzed. It was proposed that resin microspheres can be used as a good physical sensitizer of emulsion explosives. The foaming effect of resin microspheres mixed with a certain proportion of liquid paraffin, dimethylsiloxane and 32# engine oil is good, and the dust is restrained. The foaming and pumping process have little damage to the resin microspheres. Experimental results show that the best foaming temperature is 150-170 ℃. Resin microspheres with the best foaming temperature were heated and foamed after mixing with 32# engine oil, and then it was mixed with emulsion matrix for sensitization. The obtained emulsion explosive has good explosion peformances.