As the world’s largest energy importer, China’s energy security is profoundly affected by the international energy system. In the face of new changes in the pattern of energy supply and demand and new trends in international energy development, the Chinese government has put forward a new energy security strategy of “four revolutions and one cooperation.” China been continuously promoting structural reform of the energy supply side and enhancing its ability to guarantee energy security. It has also built a multi-wheel-driven supply system and has been accelerating the pace of its green and low-carbon energy transformation. However, under the influence of COVID-19 and geopolitical factors, the uncertainty and instability of the international energy market have increased, and structural contradictions in the domestic energy market still exist, so energy security is facing new challenges. This chapter focuses on the current situation of energy supply security in China to present a systematic review of the problems and challenges faced by the nation’s energy security and a summary of the opportunities and strategies for ensuring energy security in the new era.