The invention discloses a preparation method of a peach-shaped Mn2O3/C particle. The preparation method comprises the following operation steps: (1) preparing a manganese salt into a manganese salt solution, and adding a carbon source and a complexing agent, so as to obtain a mixed solution; (2) performing hydrothermal reaction at the reaction temperature of 130 to 180 DEG C, preserving heat for 15 to 30h, and cooling, so as to obtain a hydrothermal product; (3) filtering, washing, drying and grinding, so as to obtain dry powder; (4) calcining, and cooling, so as to obtain a product. By mixing the manganese salt, the carbon source and the complexing agent, and using a hydrothermal method to form an Mn2O3/C precursor, and calcining at high temperature, the peach-shaped Mn2O3/C particle is finally obtained. The preparation method has the advantages that the technology is simple, the repeatability is high, the price of used raw materials is low, and the source is wide; the final reaction product is a metal oxide and carbon composite material, has not toxicity, and is environment-friendly.