The invention discloses a battery pack equalization method based on sliding mode control. A special battery equalization topological structure is designed according to the disequilibrium situation of series battery packs; a mathematical model is established for the battery equalization topological structure, and a battery equalization system mathematical model formed by the battery equalization topological structure and the series battery packs together is established; and equalization control is performed by using a sliding mode controller through combination of the battery equalization system mathematical model so that equalization processing between all the batteries in the series battery packs can be realized. Battery equalization can be rapidly performed by the method so that the energy can be effectively saved and the battery life can be enhanced.