The perfluoroether rubber had excellent properties of resistance of high and low temperature as well as special medium.The 7804 grease was used as lubricant of perfluoroether rubber sealing material when applied in radial sealing.In this paper，the sealing performance of perfluoroether rubber sealing material in radial sealing was studied.The results show that perfluoroether rubber seal has low gas leakage rate.After 7804 grease coated on perfluoroether rubber sealing material for a period of time，some small particles from grease is generated，which can form micro-channel on the surface of rubber，results an increase on the leakage rate when tested by helium mass spectrometer leak detector.The use of liquid fluoroether raw rubber as lubricant can reduce the leakage rate effectively.The gas leakage rate of perfluoroether rubber sealing material coated with 7804 grease in oxidant and combustion agent medium is much lower than that in helium environment，which means that 7804 grease can be used as the lubricant of perfluoroether rubber sealing material in special medium environment.