The utility model discloses a grain depot heat preservation airtight door which comprises a door frame, a door leaf and a stile, the door frame is installed on a wall body, the door leaf is matched with the door frame, the stile is connected to the side, close to the door frame, of the door leaf, the stile is connected with the wall body through a hinge, and a first sealing strip is arranged between the stile and the wall body. A second sealing strip is arranged at the joint of the stile and the door leaf, angle iron is arranged on the inner side of the door frame, a third sealing strip corresponding to the second sealing strip adheres to the side, close to the stile, of the angle iron, and a fourth sealing strip is installed on the side, away from the stile, of the angle iron. The double-layer sealing structure is simple in structure and convenient to use, two sealing defensive lines are arranged, double-layer sealing is achieved, and therefore long-acting and stable sealing performance of the grain warehouse is guaranteed.