The invention discloses a solar energy and geothermal energy co-generation system, which consists of a solar hot air flow generation system and at least one geothermal heat pipe generation system; in the solar hot air flow generation system, a turbine generator set is arranged at the bottom of a solar chimney which is in smooth transition connection with a solar heat collection shed; the geothermal heat pipe generation system is installed below the solar heat collection shed; and in the geothermal heat pipe generation system, an evaporation cavity is in sealed connection with a condensation cavity through a tapered pipe cavity, and a generation device is installed in the condensation cavity. The invention has the advantages of simple structure, high degree of automation, effective utilization of the solar energy and geothermal energy, environment-friendly and low-cost operation and maintenance and continuous, stable and efficient generation, practically contributes to energy conservation, emissions reduction and the like, and promotes the sustainable development of cyclic economy.