In order to improve the combustion efficiency of Al powder， Al/modified-fluororubber composite fuel（FKM-GW@Al） was prepared with the silane modified-fluororubber（FKM-GW） by sol-gel method. The stability of FKM-GW@Al in solvent was studied， and the results show that with functional groups， the FKM-GW@Al is stabile in ethyl acetate. The application of FKM-GW@Al in NEPE high-energy and low burning-rate solid propellant was studied. Results show that compared with Al powder， FKM-GW@Al with fluorine mass fraction 2.58%， make the explosion heat of the propellant increase from 6348.8 J·g^-1 to 6831.6 J·g^-1， the content of activated aluminum in residues decreased from 1.02% to 0.06%， and both the static and dynamic burning rates of the propellant containing FKM-GW@Al decrease. The thermal decomposition properties of FKM-GW@Al and the propellant containing FKM-GW@Al were studied by DSC-TG， and the influence mechanism of FKM-GW@Al on combustion characteristics of the propellant was analyzed.