In this paper, emulsion explosives were investigated. Rules for the change of output energy of emulsion explosives with different oxygen balance, aluminum powder content, charge condition, decoupling media etc. were studied by means of an explosion water pool. The pt curves and peak pressure values were obtained. The effects of these factors on shock wave energy, bubble energy and total energy were given. The results show that output energy of emulsion explosives without aluminum powder is lower than that of standard TNT explosives. The total energy of emulsion explosives with zero oxygen balance is only 86?% of that of TNT. In the experiment, output energy of the explosives tends to increase with the increase of aluminum powder content. With aluminum contents from 10?% to 15?%, the total energy is 1.05 and 1.14 time of that of TNT respectively. Energy efficiency is affected with change of decoupling coefficient and media.