The invention discloses a solar grain drying device which comprises an elevator, a drying tower, an air cooler, a solar hot-air blower, a heat exchanger and a hot-blast stove. The elevator is fixed onone side of the drying tower, and a discharge port in the upper end of the elevator communicates with a feed port in the top end of the drying tower; the air cooler is arranged on one side of the drying tower, and an air outlet communicates with a cooling bin; the hot-blast stove is connected with one end of the heat exchanger, the other end of the heat exchanger is connected with the solar hot-air blower, and an air outlet of the solar hot-air blower communicates with a first heating bin, a second heating bin and a drying bin through pipelines. According to the device, the drying efficiencycan be improved, the drying quality can be guaranteed, and multi-stage heating and tempering can be adopted.