A lifting mechanism includes a lifting beam, a hanging portion suspended below the lifting beam and including a hanging base, a hanging chain, a movable sprocket disposed on the hanging base, a distance adjusting sprocket, and a power mechanism. The distance adjusting sprocket and the power mechanism are arranged side by side and separately on the lifting beam. The power mechanism includes a fixed sprocket and a driving portion. The fixed sprocket is driven by the driving portion to drive the hanging chain to move, so as to lift or lower the hanging portion. An end of the hanging chain is fixed to the lifting beam, and the other end of the hanging chain engages the movable sprocket, the fixed sprocket, and the distance adjusting sprocket, or the other end of the hanging chain engages the movable sprocket, the distance adjusting sprocket, and the fixed sprocket.