The invention discloses a preparation method of spherical nanometer cobalt alloy powder containing transition metal elements, belonging to the technical field of the preparation of superfine nanocrystalline WC-Co hard alloy raw material powder. The method comprises the following steps: mixing the aqueous solution of soluble cobalt salt, the aqueous solution of soluble transition metal salt and the aqueous solution of soluble carbonate or bicarbonate to prepare a basic cobaltous carbonate precipitate containing transition metal elements, cleaning repeatedly, separating out the precipitate, performing vacuum drying on the precipitate, decomposing, and reducing with hydrogen, thus obtaining the spherical nanometer cobalt alloy powder containing transition metal elements. The invention provides a new technology for performing efficient large-scale continuous production of the spherical nanometer cobalt alloy powder containing transition metal elements for the production of the superfine/nanocrystalline WC-Co hard alloy. Most of the existing industrial production equipment can be used; and the method provided by the invention has the advantages that the investment cost is low, and the production scale is easy to expand. The method provided by invention can be popularized in the production of the hard alloy using nickel, iron, alloy of nickel or iron or other metals as adhesives.