The processing property and mechanical property of a medium-temperature curing high-temperature epoxy resin was introduced.The toughness of this epoxy is well, and the prepreg can co-cure with the honeycomb directly.The roll peel strength of the sandwich structure is high.The hydrothermal property of the carbon fiber reinforced composites is well, and the mechanical property is satisfied the requirement.The glass-transition temperature of the composites is high, and the heat resistance property is well.