Abstract: In high power fiber laser system, the cladding power stripper can remove cladding light to ensure the quality of the output laser beam. The fiber end-cap reduces the optical power density of the output fiber end by expanding the output laser beam, so as to protect the fiber end face. Both of them are important core devices for stable operation of high power fiber laser system. In this paper, the integrated design of cladding power stripper and fiber end-cap is carried out. The integrated high power cladding power stripper and fiber end-cap is applied to a 20 kW beam combination system and a single fiber system. When the output power is 20 kW, the maximum temperature of the end-cap is about 40 ℃ and the temperature rise rate is about 0.8 ℃/kW.