Steam label shrinking device

The invention discloses a steam label shrinking device capable of greatly reducing energy consumption. The steam label shrinking device comprises a conveyer belt, wherein a mounting rack is arranged at the outer side of the conveyer belt, a label shrinking cylinder is arranged on a top plate of the mounting rack, a label shrinking piston rod is downwards vertical and is fixedly connected with a cover body, the cover body comprises a tubular body, a top cover is arranged on the top of the tubular body, the tubular body and the top cover form a containing cavity with a downward opening, the tubular body is hollow and forms a steam containing cavity, a plurality of through holes are formed in the inner wall of the tubular body, a steam conveying pipe communicated with the steam containing cavity and provided with a control valve is connected onto the cover body, a retaining device on the mounting rack can retain a water barrel right below the cover body, at the moment, the label shrinking cylinder drives the cover body to move downwards until the opening of the water barrel is contained in the containing cavity of the cover body, and after the label shrinking cylinder drives the cover body and the water barrel to be separated from each other, the retaining device does not retain the water barrel and the water barrel is continuously conveyed through the conveyer belt.