Abstract: General Secretary Xi Jinping has emphasized the importance of building a new energy system to address energy challenges and promote sustainable development. This paper discusses how to build a new green and low-carbon energy system by optimizing the energy structure through the integration of multiple energy resources, including water, wind, light, hydrogen and natural gas. In the development of new energy sources, attention is not only paid to traditional renewable energy sources such as solar energy and biomass, but also emphasizes the parallel development of new forms of energy such as geothermal energy and wave energy. Ocean thermal cycle energy, hydrogen energy and methanol are seen as key to future energy. In the face of the challenges posed by the randomness and intermittency of new energy generation, an integrated strategy of "source, grid, load and storage" is proposed to strengthen the real-time balance and complementarity of the energy system. The new energy system aims to promote the transformation of "coal, electricity, oil and gas" to "cold, heat, electricity and hydrogen" new quality productivity, and promote the sustainable development of the energy industry. New energy sources replace traditional energy sources to realize green and low carbon, while traditional energy sources provide regulating services for new energy sources to ensure system stability. The construction of a new energy system will promote the energy industry's "coal, electricity, oil and gas" and "cold, heat, electricity and hydrogen" new quality reconstruction. This means replacing coal, oil and natural gas with electricity, and utilizing new energy sources to produce electricity, cold air, heat and hydrogen, cultivating new productivity in the energy industry. This transformation will promote the sustainable development of the energy industry and provide stable energy support for socio-economic development.