Abstract: This paper takes the solar-ground-source heat pump composite system applied in rural residential areas around Xi’an as the research object,and uses TRNSYS software to model the composite system.Firstly,the parameter calculation methods of the main components in the composite system are described in detail.Secondly,the inclination angle of solar collector and the volume of hot water storage tank in the composite system are analyzed.Finally,the operating conditions of the composite system are optimized from the perspectives of the heat collection of the solar heat collection system,the energy consumption of the groundsource heat pump system and the COP.The research results show that in the whole heating period,when the inclination angle of solar collector is 52°and the volume of hot water storage tank is 0.45 m~3,the total energy consumption of the whole composite system is the lowest.Meanwhile,the total energy consumption of the optimized composite system is 1089.6 kWh,the average COP of the ground-source heat pump composite system during operation is 3.5371,and the acumulated heat collection of the solar collector is 327.3 kWh.The research results lay a foundation for the design and optimization of the application of solar-ground-source heat pump composite system in Xi’an and its surrounding areas,and are of great signi?cance for achieving the goal of emission peak and carbon neutrality.