In order to solve the high energy consumption of buildings in cold season, a ground-source heat pump assisted by the solar photovoltaic/thermal system (PV/T-GSHP) can be used. A civil building in Beijing was taken as the research object. The transient system simulation code TRNSYS was adopted to analyze the PV/T-GSHP system performance during heating season (November 2018 to March 2019). Four different temperature control strategies were established based on the local climatic conditions and performance parameters of system equipments. The numerical results were also compared with those of the traditional ground-source heat pump (GSHP) system. The results indicate that the photoelectric and photothermal conversion efficiencies of the PV/T system reach 15.0% and 46.6%, respectively. Compared with the tradional GSHP system, the coefficient of performance and the overall coefficient of performance of the system are increased by 6.9% and 10.3%, respectively. The soil temperature drop of the PV/T-GSHP system is only 8.0% according to a long-term simulation of 10 years.