The invention discloses a clean production method for high-purity cobaltosic oxide powder. The method comprises the following steps: using metal cobalt as an electrolytic anode, using soluble cobalt salt as electrolyte main salt and adding additives; adopting an electrochemical method to prepare a cobaltosic oxide precursor sediment; and then, drying and calcining the precursor sediment to obtain the cobaltosic oxide powder. The cobaltosic oxide powder produced by the method and the process can achieve the purity more than 99.7 percent, no additional precipitator is needed in the whole technological process, the added additives are all easy to wash without decomposition, and electrolyte and washing water can be recycled so as to avoid discharging sewage and generating waste gas. The method can adjust and control the appearance and the grain diameter distribution of the cobaltosic oxide powder by controlling the composition of the electrolyte, the cathode current concentration, the electrodeposition time and the calcining temperature and has the advantages of high product quality, simple production procedures, energy saving, environmental protection, and the like.