Abstract: The practical new invention is nitrogen filling grain storage device which relates to food storage area. The best way to store food is oxygen deaeration, however, maintaining the anaerobic environment through seal and vacuum in a great volume silo is hard to achieve because of many technical problems. The practical new invention adopts nitrogen grain storage technology. Nitrogen tank linked to pressure reducing valve, a flow meter and air intake circulation blower by pipeline, then enters grain piles through upside and bottom nitrogen circulation pipelines. Nitrogen spreads in the grain piles. The balanced nitrogen exhausts from the silo through nitrogen circulation outflow pipes and exhaust circulation fan. The nitrogen concentration can reach 98% after several nitrogen intake and exhaust. Stored grain in this atmosphere has the following beneficial effects: prominent grain storage effect, ability to kill all pests within 10 days, grain storage of up to 360 days and above.