Compared with the high production cost, rare earth reserves and low electrochemical stability of noble metal electrocatalysts, the preparation of non-noble metal electrocatalysts with low cost, high energy conversion efficiency, long service life and environmental friendliness is an important way to promote the development of energy storage and conversion technology. This paper reviewed monofunctional electrocatalysts, bifunctional electrocatalysts and multifunctional electrocatalysts for three important reactions in electrocatalytic process, i.e., hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). The electrochemical reaction mechanisms of water splitting and fuel cell were introduced, respectively. The design, preparation, relationship and functional characteristics was described for the monofunctional electrocatalysts, bifunctional electrocatalysts and multifunctional electrocatalysts and other electrochemical materials. The systematical characterization and resolving were performed on these promising non-noble metal electrocatalysts by using scanning electron microscopy, atomic force scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, electron energy loss spectroscopy and other complementary techniques. The surface morphology, structure, internal composition, elemental distribution and other related information were also analyzed. From the aspects of providing more defect vacancies and potential active sites, optimizing interface interaction, increasing electrochemical specific surface area, functionalizing synergistic effect, the mechanisms of improving conductivity and enhancing stability of electrocatalyst as well as reducing cost were analyzed. Expectedly, it largely promotes their large-scale applications in those involved electrochemical energy conversion and storage.