The invention discloses a curtain wall decoration system. The curtain wall decoration system comprises first glass, jet flow overlap-connected joints, second glass, a flow guiding overlap-connected claw, a supporting seat, a ventilation pipe and a main beam. The curtain wall decoration system has the following effects: the jet flow overlap-connected joints and the flow guiding overlap-connected claw constitute a connecting structure of a curtain wall hanging part, and air inside the ventilation pipe can be guided to the surface of a curtain wall sequentially through the flow guiding overlap-connected claw and the jet flow overlap-connected joints, so that air fluid disperses around the surface of the curtain wall, can blow away rainwater and dust on the surface of the curtain wall, and caneffectively prevent water and dust from mixing and flowing to the surface of the curtain wall to form water marks, and thus, the curtain wall decoration system can solve the problems that dust easilyaccumulates on the surface of the existing glass curtain wall, water and dust mix on the surface of the curtain wall during raining to generate more flow marks on the surface of the curtain wall, andif workers are hired to clean the flow marks of the curtain wall, the cost is high, and great safety hazards exist.