The output performance and stability of double-cladding all-fiber laser are both affected by the ability of stripping cladding light. The removing pump light will influence the monochromaticity and beam quality of fiber laser, cause damage to the output device and even damage optical device. The common method is recoating the double-cladding fiber (DCF) with a high index gel, which strips the cladding light quickly within the first few millimeters and makes the heat locally concentrated. A method using a group of gels to strip the cladding light is adopted. The commercial software Zemax and Matlab are used to simulate the stripping progress of cladding light, and an experimental verification system is presented. The results indicate that the proposed method can strip the cladding light gradually over the length of the fiber with an attenuation ability of 20 dB, and the thermal distribute is uniform without local temperature too high.