Airtightness detection device

The utility model relates to the technical field of aeronautical manufacturing, and particularly discloses an air tightness detection device which comprises a pressure equalizing container and a blocking rod, the pressure equalizing container is provided with an open end, and the open end of the pressure equalizing container can cover the joint of a drain pipe joint and a skin. The pressure equalizing container is configured to provide uniform and stable airflow for the joint of the drain pipe connector and the skin, the blocking rod is provided with a protruding part and detachably arranged at the open end of the pressure equalizing container, the protruding part can be inserted into the drain pipe connector to be positioned, and the pressure equalizing container can apply compressed gas to multiple nail positions at the same time. The protruding part on the blocking rod is inserted into the drainage hole of the drainage pipe connector to play a role in positioning, so that the pressure equalizing container