Faced with the dual challenges of increasing energy demand and reducing carbon emissions, it is of great significance to improve urban renewable energy utilization, reduce building energy consumption, develop integrated photovoltaic building applications, and achieve the integration of construction and new energy industries. In this paper, the public building photovoltaic system of Baoshang Bank was selected for the research. According to the unique climatic characteristics of Baotou City, Inner Mongolia, Ecotect was used to obtain the annual solar radiation model of typical building surface. Based on the optimal system configuration method, the solar energy utilization potential evaluation model of photovoltaic building was constructed from three dimensions: peak energy potential, economic potential and social potential. The research shows that the photovoltaic system of Baoshang Bank alleviates the pressure of the local power grid at the peak period with 12.5% of the total power demand during the extreme climate, and delays the peak period of energy consumption by 2 hours. The net income of photovoltaic system with 25-year life cycle is 1.0466 million yuan. When the unit cost of photovoltaic system is 7.9 yuan/W, the on-grid price is 0.8 yuan/kWh, the system investment can be recovered within 5.15 years. In addition, there is a three-dimensional coupling relationship between unit cost, government subsidy and investment payback period. The environmental benefit during the life of the photovoltaic system is 0.096 yuan/kWh, and the social benefit is 11.93 yuan/kWh. This evaluation model provides reference for the promotion of photovoltaic buildings in the city and the formulation of photovoltaic industry policies.