Abstract: The aluminizing layer was prepared by chemical vapor deposition（CVD） in the inner cavity and outer surface of cobalt-based alloy hollow blade. The thickness, surface morphology, microstructure, element concentration distribution and the influence of the layer on the mechanical properties of alloy were studied. The experimental results show that the aluminizing layer prepared on the blade surface with 1020 ℃×4 h has no defects such as warping, bubbling and cracking, the aluminizing layer is uniform and continuous. The high temperature oxidation resistance and gas corrosion resistance of the parts can be improved significantly, and the permeation layer has little effect on the durability of the materials.