Klystrons have wide range applications in key scientific engineering and industrial heating engineering because of their advantages of high power,high efficiency and long lifetime.Aiming to the ap-plication in microwave plasma chemical vapor deposition(MPCVD),a 10~15 kW miniaturized continuous wave(CW)klystron is designed.The whole weight of the klystron is below 30kg.Under the working voltage of 16kV and the electron beam current of 2 A,the output power is more than 17kW,and the effi-ciency is more than 56%.