The invention relates to a solar heat supply and heating system based on cross-seasonal soil heat storage, and belongs to the field of solar heat supply. The system comprises a heat collection device, a buffer water tank, a buried pipe heat exchange device, an auxiliary heat source, a reversing circulation pump group composed of a plurality of circulation pumps and a plurality of valves, a temperature sensor, a controller controlling the opening and closing of the valve, an electric actuator and a connection pipeline, wherein an outlet of the heat collection device is connected with the buffer water tank through a first parallel valve and a second serial valve, and the heat collection device is sequentially connected with a first circulation pump, a first valve, a third valve and the buffer water tank; an edge port of the buried pipe heat exchange device is directly connected with the buffer water tank, and a central port of the buried pipe heat exchange device is connected with the buffer water tank through the reversing circulation pump group; and the buffer water tank is sequentially connected with a heating end through the circulation pumps and the auxiliary heat source. The system disclosed by the invention solves the problems of heat waste, low assurance factor of solar energy, shortening for the lives of a heat collector and pipe valves, and the like, of an existing system, in non-heating seasons.