Abstract: Three groups of emulsion explosives were made of the same emulsion matrix mixed with 2%, 3%, 4% and 5% by the mass of hollow glass microspheres respectively in group 1, and with 2%, 3%, 4% and 5% by the mass of expanded perlite respectively in group two, and with 0.10%, 0.15%, 0.20% and 0.25% by the mass of chemical foaming agent in group 3. The explosion shock waves of all the emulsion explosives in every group were tested in water in two cases that when they were not pressed and after they were compressed by shock waves which were produced by the host charge underwater, and their pressure desensitization degrees were calculated with the peak pressure values of tested shock waves. The pressure desensitization degrees of the emulsion explosives in every group were compared and the influence of their density on the pressure desensitization was analyzed. An emulsion explosive with higher density has a lower pressure desensitization degree.The higher the mass content of expanded perlite or chemical foaming agent mixed with emulsion matrix, the more easily the pressure desensitization of the emulsion explosive occurs.When the mass content of hollow glass microspheres mixed with emulsion matrix increases from 2% to 4%, the pressure desensitization degree of the emulsion explosive increases.But the mass content of hollow glass microspheres mixed with emulsion matrix increases from 4% to 5%, the pressure desensitization degree of the emulsion explosive decreases.Emulsion explosive density influencing its pressure desensitization is mainly due to the emulsion breakage around the density regulator particulates.