Restraining the shuttle effect and improving the cycling durability of lithium-sulfur (Li-S) batteries are the basic premise to realize its large-scale application, while the adsorption and catalytic capacities of the host to polysulfide lithium (Li₂S_n, 4 ≤ n ≤ 8) is the key to affect those performances. Therefore, in this work, yolk-shell porous carbon spheres loaded with CoSe₂ nanosheets (THC-CoSe₂) are synthesized as hosts for Li-S batteries. Due to the unique microstructure, as-constructed S@THC-CoSe₂ cathode not only can relieve the volume expansion of active substance, but also offer a “multilayer defensive system” to prevent the outward diffusion of Li₂S_n through physical and chemical interactions simultaneously. In addition, the outermost CoSe₂ nanosheets with excellent electronic conductivity is able to catalyze the transformation of Li₂S_n anchored on its surface, finally accelerating the elimination of soluble intermediates and weakening the shuttle phenomenon. Based on above advantages, the initial discharge capacity of the Li-S battery assembled by S@THC-CoSe₂ cathode is as high as 1230.0 mAh g⁻¹ at the current rate of 0.1C, and the capacity attenuation of each cycle is as low as 0.034% in 1000cycles at 1.0C.