The purpose of the integrated application of solar systems and geothermal energy is to complement each other perfectly and to fully utilize renewable resources for low-carbon and energy-saving ideas. In this paper, the application of the composite energy system in the engineering design of a project in Wuhan which belongs to hot summer and cold winter area will be evaluated in such aspects, including technical feasibility, system efficiency, economic and environmental impacts, in order to provide technical and practical experience for the design and application of integrated energy systems in the future.