Co₃O₄ catalysts with three specific morphologies (nanocubes, nanosheets, and nanooctahedra) were prepared using simple preparation methods and tested for catalytic combustion of propane under the same reaction conditions. Co₃O₄ nanosheets (Co₃O₄-S) with the highest Co²⁺ content presented the best catalytic activity among the three catalysts and achieved complete oxidation of propane at 210 °C compared with 320 °C for nanocubes and 400 °C for nanooctahedra in our work. It is confirmed by XPS characterization that there were a large number of surface hydroxyl groups on the surface of Co₃O₄-S, and they were more inclined to attach to Co²⁺ species, whereas the amount of hydroxyl groups on the surface of the other two catalysts (nanocubes and nanooctahedra) was negligible. DFT calculations indicate that the bond energy between a hydroxyl group and surface Co²⁺ is higher than that between a hydroxyl group and surface Co³⁺, which proves that hydroxyl groups are more likely to be attached to Co²⁺ on the surface of Co₃O₄-S. The hydroxyl groups on the surface of Co₃O₄-S altered the intermediates and the reaction pathway in the process of propane oxidation, which greatly enhanced the catalytic activity of Co₃O₄-S. This research can open up a facile and reliable strategy for the design and construction of efficient propane oxidation catalysts by modifying the functional groups on the surface of the catalysts.