The desensitized triple base propellants containing NGu were prepared by polymer deterrent technology with and without saturator, their surface structure were charactericed by electron microscopy and combustion characteristics were investigated by means of the ignition test, closed-bomb tests and interior ballistic tests. Results show that there does not exist the surface structure destroy and the ignition characteristics is good for propellant desensitized with the saturation agent. The ignition time is prolonged. The propellant with the saturation agent has great combustion progressivity and good interior ballistic at the same time.