The invention provides a PVT heat pump system capable of achieving day and night time-division heat, power and cold supply through solar radiation and sky cold radiation, and a photovoltaic power generation technology and a PVT heat pump technology which are relatively independent and mutually promoted in function are used simultaneously. Solar radiation energy and sky long-wave cold radiation energy are used as main energy resources of the system, and the energy is converted into electric energy, heat energy and cooling capacity through a PVT photoelectric-evaporation/condensation assembly in different modes at different times. The system integrates the various functions of power generation, heating, cooling and the like, equipment composition is simple, the equipment utilization rate is high, the energy saving effect is remarkable, the energy utilization rate is increased to the greatest extent, and the effects of achieving multiple purposes through the system and achieving day and night time-division heat, power and cold supply are achieved.