How to reduce the wear rate of the cylinder and complementary set bag of FL-300 spraying dryer granulator were studied. According to the working principle of the cylinder and the installing way of the complementary set bag, the wear rate was reduced under condition that FL-300 spraying dryer granulator operated normally. The reasons of the wearing of the cylinder and complementary set bag were analyzed, and the key factors of the wearing were found out. The wear rate of the cylinder and complementary set bag of FL-300 spraying dryer granulat were reduced  by improving the equipments, and the changing frequency was reduced. The results showed that the wear rate of the cylinder and complementary set bag of FL-300 spraying dryer granulator were obviously lowered by this methed.