The invention provides a method for effectively enlarging the surface area of a micro-nano electrode particle and relates to a method for enlarging the surface area of an electrode. The method disclosed by the invention aims to solve the problem that an existing solid oxide fuel cell electrode is small in surface area. The method comprises the following concrete operating steps of 1, preparing a precursor solution; 2, stirring, evaporating to dryness, reducing and sintering; 3, carrying out acid washing; and 4, washing and drying. The method for effectively enlarging the surface area of the micro-nano electrode particle, provided by the invention, has the advantages that 1, the method is easy to operate, convenient, rapid and high in preparation efficiency; 2, the preparation of the particle is simple, no expensive instrument or equipment is needed and compared with a commonly used ion etching technique, the method is capable of reducing the preparation cost; 3, compared with the surface area of a primary micro-nano electrode particle, the surface area of the micro-nano electrode particle obtained by the invention is increased by 1.4-1.8 times. By means of the method, the surface area of the micro-nano electrode particle can be enlarged.