The invention discloses a preparation method of palladium acetate. The method includes steps of, firstly, taking a metal palladium as a raw material, and dissolving the metal palladium by hydrochloric acid and hydrogen peroxide to obtain the dissolving liquid; adjusting pH value of the dissolving liquid by alkali solution to obtain turbid liquid; stirring for 1 hour to obtain a reaction liquid; secondly, adding glacial acetic acid in the reaction liquid, heating and stirring; after reaction, cooling and filtering; washing the filtered solid by water and then drying the solid to obtain palladium acetate. The preparation method breaks through an existing method of applying nitric acid or oxynitride as the assistant agent to produce palladium acetate, avoids environmental pollution, and is less in environmental pollution; the preparation method is simple and easy to control and operate, and convenient to scale production.