The invention relates to a technical field of grain storage safety control, and discloses a grain storage safety control system and a grain storage safety control method. The grain storage safety control system comprises a temperature detection device and a control device, wherein the temperature detection device is used for detecting temperature of a plurality of positions in a granary; and the control device is used for determining a ventilation mode according to the detected temperature of the plurality of positions in the granary, and controlling corresponding ventilation equipment to operate according to the determined ventilation mode. According to the grain storage safety control system and the grain storage safety control method, the ventilation mode is automatically determined according to the detected temperature of the plurality of positions in the granary, the corresponding ventilation equipment is controlled to operate according to the determined ventilation mode, and the effect of automatically controlling the ventilation equipment according to temperature in the granary is realized, thus the temperature control in the granary does not require manual participation, and good control effect can be achieved.