The invention relates to a method for preparing cobalt oxide, nickel oxide and copper oxide, in particular relates to a method for preparing the oxide of the cobalt (Co3O4, Co2O3), the oxide of the nickel (NiO), the oxide of the copper (CuO), and the like. The minerals containing the cobalt, the nickel or the copper are adopted as the raw material; after the minerals is dipped and purified to get high-purity cobalt salt, nickel salt or copper salt solution; the salt solution is made into the mist-shaped liquid drop in the mist spraying way; the cobalt oxide, the nickel oxide or the copper oxide can be prepared through the dehydration, high-temperature hydrolysis and the crystal-shape re-shaping; the tail gases such as the vapor and the acid gases that are generated in the hydrolysis process are absorbed by a leaching tower to get the acid, and the acid is returned to be used for the dipping and purification process of the minerals, thereby realizing the comprehensive cycling application in the preparation process. The method can also be used for processing the waste material containing the cobalt, the nickel or the copper. The invention has the advantages of advanced process, stable production, low cost, no waste water discharging, environmental protection, high purity of the product, uniform granularity, high crystallization, and the like.