The invention relates to the field of special equipment or measurements relating to doors and windows and discloses a high airtightness door comprising a door frame and a door leaf. One door edge of the door leaf is hinged to the door frame, and active racks are arranged on remaining door edges of the door leaf. The tooth faces of the active racks face the door frame. The active racks are parallel to the rotating path of the door leaf. Active gears are arranged in the positions, corresponding to the active racks, of the door frame. The active gears are matched with the active racks. The door further comprises slave gears and slave racks. The slave gears are engaged with the active gears. The slave racks are engaged with the slave gears. Sliding grooves with lubricating grease are formed in the door frame. The slave racks are slidably connected in the sliding grooves. Sealing strips are arranged at the ends, facing the door leaf, of the slave racks. Containing grooves containing the sealing strips are formed in the door frame. The active racks and the slave racks both are in an arc shape. According to the high airtightness door, the airtightness of the door is increased, and air leakage from gaps of the door edges is avoided.