Air tightness detection device applied to battery case

The utility model discloses an air tightness detection device applied to a battery case. The air tightness detection device comprises a sealing mechanism and a pressing mechanism used for pressing the battery case on the sealing mechanism. The sealing mechanism comprises a U-shaped frame body, and two ends of the U-shaped frame body are respectively provided with a hydraulic cylinder group I and a hydraulic cylinder group II which are used for pressing two sides of the battery shell; a silica gel plate is arranged on the end surface, in contact with the battery shell, of the U-shaped frame body; the U-shaped frame body is covered with a battery shell, the battery shell and the U-shaped frame body form a sealed cavity through the hydraulic air cylinder set and the pressing mechanism, and an air tightness detector is arranged in the sealed cavity. According to the utility model, the sealing mechanism matched with the appearance structure of the battery shell is matched with the pressing mechanism, so that the o