Abstract: Air source heat pump (ASHP) systems have been widely adopted in civil building heating due to their high energy efficiency, environmental friendliness, low operating costs, and simple structure. Some significant challenges still remained in their widespread application in the high-latitude severe cold regions. Extremely low temperatures can lead to a substantial decline in the coefficient of performance (COP) of the ASHP systems, directly limiting their large-scale adoption for the livestock building heating in these areas. Among them, the COP has been one of the most important parameters to evaluate the suitability of ASHPs in frigid climates. The real-time COP measurement data under extreme weather conditions can also hold the crucial theoretical and practical value in the livestock farming industry. The ASHP technology can exhibit significant advantages in utilizing the low-grade energy sources. However, the electricity is often required for the fossil fuels at present. Alternatively, renewable energy power supply can be expected to further enhance the energy-saving and emission-reduction potential of heat pump systems. This study aims to systematically investigate the photovoltaic (PV) system’s power generation efficiency at different times of the day, as well as the coupling efficiency between PV power generation and ASHP operation. The PV-ASHP heating was then optimized to evaluate the COP and the PV power generation efficiency during the coldest season in severe cold regions. A PV-driven ASHP heating system was established for a goose house in Anda City in Heilongjiang province. The ASHP system consisted of three subsystems: the heat pump heating unit, heat production monitoring, and the electricity consumption monitoring system. Meanwhile, the PV power generation was composed of three components: PV modules, inverters, and grid-connected control cabinets. As such, the power generation-conversion-grid was integrated into one complete system. Systematic experiments were conducted to acquire the operational data during the coldest periods between January and February 2024. The results indicated that the heating capacity and supply/return water temperature shared positive correlations with the outdoor ambient temperature under constant flow operation mode, while the heat pump's input power and temperature difference between supply and return water remained relatively stable. The COP of the ASHP demonstrated that there were significant correlations with both heating capacity and outdoor temperature. The full-day average COP reached 1.81 under extreme cold conditions with a daily average temperature of -21.31℃. There was then a decrease to 1.21, when the temperature dropped to -28.99℃. The performance tests of the PV system revealed that the maximum daily power generation reached 37.3 kWh, with an average daily output of 27.6 kWh and a peak instantaneous power of 6 211.2 W. The instantaneous PV power generation maintained a stable positive correlation with the solar radiation intensity under various weather conditions. The PV modules were evaluated as a peak power of 7.98 kW, according to the rated input power (7.0 kW) of the ASHP under standard heating conditions. The operational data revealed that this configuration only achieved a 16.7% power self-sufficiency rate. Therefore, it is recommended to increase the PV array capacity, and then integrate an energy storage system in the practical engineering applications, in order to enhance the performance of the PV system. This finding can also provide the technical references and data support for the optimal control of PV-ASHP heating systems in severe cold regions.