Abstract: In order to cope with the continuous aggravation of environmental pollution and the growing shortage of fossil fuels, promoting the implementation of the "double carbon" goal, and building a modern energy supply system, and continuously increasing the grid-connected proportion of renewable energy, such as wind power and photovoltaic in the system, which has brought challenges to the construction of novel power system. Renewable energy power generation is intermittent and fluctuating, and the access location is scattered, which increases the difficulty of safe and stable operation of the power system. The proposal of virtual power plant provides a new idea for solving the problems of renewable energy, ensuring energy security and maintaining power system stability. This paper expounds the basic structure of virtual power plant, and analyzes the key technologies from three aspects of market operation technology, coordinated and optimized operation technology, and Internet of things technology. It also introduces the market transaction structure from the perspective of platform level and multi-flow integration, and analyzes the multi-level market modes of the virtual power plants participating in auxiliary services, medium and long-term, spot and so on, which provides reference for the construction and development of the virtual power plants participating in the power market in China.