Heat handling has been a significant problem of the high power fiber laser systems as the output power increases rapidly. Cladding power stripper (CPS) which is used to deal with the unwanted optical power and light is required for higher cooling ability. So the methods of stripping the unwanted light attracted much attention recently, and the thermal effect is given. However, few investigations focus on the dissipation of the heat converted from the unwanted light. In this paper, an approach of active cooling for CPS is demonstrated. This is achieved by using microchannel cooling technology in heat sinking in CPS to improve the efficiency of heat exchange. In order to explain the mechanism of CPS the function of it and consistence of categories of the unwanted light are detailed firstly. Then microchannel heat sinking is proposed and verified by the heat exchange theory. At last, the design of the CPS with microchannel heat sinking is shown and following experiment is conducted. The final temperature of the device with 1000 W cladding power was demonstrated at last to verify the ability of heat distribution of the CPS component. This suggests that these CPSs can be used to stripe a thousand of watts of light in high power double cladding fiber lasers.