Blockchain is one of the currently disruptive science and technology. Its centralization, openness, transparency and immutability are compatible with the concepts of openness, reciprocity, interconnection and sharing of energy and power systems. The application of blockchain technology in energy and power systems will change the traditional energy trading methods and management modes, which can reduce the operating costs of the system, improve the security of the system, and benefit the development of energy and power systems. This article summarizes and analyzes the basic concepts of blockchain technology, the demand for blockchain technology in the field of energy and power systems, and the typical application scenarios of blockchain in the field of energy supply, energy transmission and distribution, energy consumption and energy trading. Finally, the challenges of the application of blockchain technology in energy and power systems are analyzed and prospected.