The invention relates to a preparation method of doped carbon microspheres, particularly a preparation method of nitrogen-doped carbon microspheres, which aims to solve the technical problems of high facility request and harsh reaction conditions in the existing preparation method of the exotic-atom-doped carbon material. The method comprises the following steps: 1. adding o-toluidine into a H3PO4 water solution, stirring uniformly, sequentially adding a H2O2 water solution and a FeCl3 water solution, and stirring uniformly to obtain a precursor solution; 2. transferring the precursor solution into a reaction kettle, carrying out hydrothermal synthesis, separating, cleaning and drying to obtain poly-o-toluidine microspheres; and 3. roasting the poly-o-toluidine microspheres in a vacuum tube furnace under the protection of nitrogen to obtain the nitrogen doped-carbon microspheres. The nitrogen-doped carbon microspheres can be used as a fuel cell high-efficiency ORR electrocatalyst and a supercapacitor electrode material.