Composite panel/ aluminium sandwich structure was fabricated by the co-curing process. The effect of processing pressure on the properties of composite panel was investigated to determine the co-curing pressure. The properties of aluminium honeycomb with different dimension parameter and their sandwich structures were also tested and analyzed. The results show that the processing pressure has little effect on the properties of thin composite panel. The sandwich structure fabricated by the aluminium honeycomb of 0. 04 mm×4 mm has high specific strength and modulus, and is easier to fabricate. Therefore, it has more widely potential applications.