In the last three decades,rotary magnetron sputtering cathodes are widely used in the feld of large-area thin flm preparation.Achieving a stable status and uniform of process gas distribution plays a vital role in obtaining uniform thickness of the coating flm.This paper presents a new type of rotary sputtering cathode gas distribution unit,which consists of a main distribution pipe which mixture gases can escape from,and a fve-phase distribution pipe which can fne-tune the composition of the whole pipeline system.The whole pipeline system is set in a aluminum cavity which is extruded and has one end elongated rectangular opening.The gas fow in the gas transport pipeline is adjusted by the fow controller,which is precisely controlled by the fow control system via the PLC.The FLUENT software is applicated for modeling the structure of the gas distribution.By analysising the law of gas distribution when varying the number of nozzles,nozzle cross-sectional area,the width of rectangular opening of the aluminum cavity,the gas distribution device is optimized,to achieve a uniform distribution of gas in the sputtering chamber.