With the expansion of ammonium nitrate crystal reactor，operating load of the machine increases，vibration and noise of stirring apparatus of the reactor rise. Further more，a number of problems appear，such as intensifying the abrasion of bearings and fillers of the stirring apparatus，reactor being not seal well and other problems. Binding experiment, improvement fundamentals to these equipments were put forward, the mixer frame，mixer bearing seal，filler，spherical tank head and vibration damper were redesigned.Then the vibration and noise of stirring apparatus of the reactor are solved, the service life of bearing and filler of stirring apparatus are extended, productivity and product quality are increased.