The present invention provides a doped cobalt carbonate preparation method. The preparation method comprises the following steps: cobalt carbonate is prepared; the cobalt carbonate is added into a metal alkoxide solution to be mixed to obtain the cobalt carbonate wrapped by the metal alkoxide; and the wrapped cobalt carbonate is dried to obtain a doped cobalt carbonate. The present invention also provides the doped cobalt carbonate prepared by the doped cobalt carbonate preparation method, a doped tricobalt tetroxide preparation method, and a doped tricobalt tetroxide prepared by the doped tricobalt tetroxide preparation method. The doped cobalt carbonate preparation method and the doped tricobalt tetroxide preparation method can prepare the doped cobalt carbonate and the doped tricobalt tetroxide which are uniform in particle sizes, evenly coated, and large in particle sizes, respectively.