In the process of eliminating the residual pump light and high-order laser light, the cladding power stripper (CPS) generates abundant heat, which can affect the performance of the fiber laser system due to the photothermal conversion. Hence the efficient dissipation of thermal energy becomes a current research focus. In this paper, the five kinds of existing CPSs are simulated and compared with the results in the literature. It is found that the surface-volume ratio between the heat source and the heat transfer medium can be effectively increased by changing the shape of the polymer filling hole when the CPS is made by the high refractive index polymer method, thus reducing the temperature peak and valley value of the CPS. Besides, the heat distribution uniformity of CPS can be improved by combining the high refractive index polymer method with the acid corrosion method to prepare the two-section fiber cladding structure with uneven thickness. According to the above results, a novel CPS structure is proposed and its thermal effect is studied. The results show that when the cladding light power is 150 W, the temperature peak value of the CPS is 298 K, the temperature valley value is 293 K, and the temperature difference is 5 K. Comparing with the above five CPSs, the peak temperature is reduced by up to 11.3%, and the valley temperature is reduced by up to 8.4%, the temperature difference is reduced by up to 87.5%, which proves that the novel CPS structure can effectively suppress the temperature rising and have excellent heat distribution uniformity.