Smart energy is the foundation and important component of smart cities, and it is the source of energy that guarantees the efficient and reliable operation of each subsystem of the city. Based on the practical experience in the exploration of the construction of smart energy at home and abroad, and the goal of achieving “three transformations and one center”, the basic principles of the frame construction as well as display construction and physical construction of smart energy have been proposed. Four main tasks of the construction of smart energy have been discussed: infrastructure, energy supply, energy consumption, and management services.