The invention discloses a mid-and-low temperature solar energy-biomass gasification polygeneration system. The system comprises a biomass preheater, a biomass crusher, a circulating fluidized bed gasifying furnace, an electric deduster, a first heat exchanger, a second heat exchanger, a condenser, a water pump, a trough solar energy collector, a gas turbine, a flue gas hot-water absorption unit and a third heat exchanger. The system couples and integrates two types of renewable energy comprising biomass and a mid-and-low temperature solar energy, and realizes step utilization of different grades of energy. The overall energetic efficiency of the system reaches up to 76.9%, and the system plays a great role in energy structure optimization, waste heat utilization and environmental protection.