The invention discloses a preparation method of a manganese-doped sodium-ion battery positive electrode material, which comprises the following steps: dissolving one or two of antimony trioxide and bismuth trioxide with acid, adding a divalent manganese salt to prepare a mixed metal salt solution, adding the mixed metal salt solution into an alkaline oxidant solution, and reacting to obtain the manganese-doped sodium-ion battery positive electrode material. And carrying out solid-liquid separation to obtain a solid material, drying the solid material, mixing the solid material with a sodium source, and sintering to obtain the manganese-doped sodium ion battery positive electrode material. The antimony or bismuth element is doped, the skeleton structure of the material is enhanced, the phase change of the material in the charge-discharge process is inhibited, the specific capacity, the cycle performance and the rate capability of the material can be obviously improved, the mixed metal salt solution is dropwise added into the excessive alkaline oxidant solution, manganese ions are oxidized into manganese dioxide, and the specific capacity, the cycle performance and the rate capability of the material are improved. Antimony and bismuth are co-precipitated with manganese dioxide in the form of hexahydroxy sodium antimonate or sodium bismuthate, so that the uniformity of doped elements of the material is ensured, and atomic-scale mixing of the elements is realized.