In order to improve the compatibility of bisphenol F epoxy resin with the liquid oxygen, the hexabromocyclododecane and the antimony trioxide were added to bisphenol F epoxy resin, and then cured resin was mechanically impacted according to ASTM D-2512-95. The microstructure and the surface element compositions of the specimen before and after the mechanical impact were investigated and analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. These results indicated that the addition of the antimony trioxide was favorable to help the hexabromocyclododecane to improve the compatibility of the bisphenol F epoxy resin with liquid oxygen. The liquid oxygen compatibility mechanism and the synergistic effect of the hexabromocyclododecane and antimony trioxide on the improvement of compatibility of bisphenol F epoxy resin with liquid oxygen were analyzed in detail.