Granary circulating fumigation device

The utility model discloses a granary circulating fumigation device which comprises a granary, ventilation ground cages are evenly laid at the bottom of the granary, an exhaust port connected with the ventilation ground cages is formed in one side of the bottom of the granary, an air inlet for conveying chemical agents is further formed in the outer top of the granary, and a spraying pipeline connected with the air inlet is arranged at the inner top of the granary. The outer side of the granary is connected with a fumigation circulating device for extracting chemical agents in the granary, the fumigation circulating device comprises a circulating chamber, the circulating chamber is provided with a granary air exhaust port, a granary air blowing port and a fumigation air exhaust port, the fumigation air exhaust port is connected with the chemical agent tank, the granary air exhaust port is connected with the air exhaust port, and the granary air blowing port is connected with the air exhaust port. The granary