Modulating the electronic configuration of the substrate to achieve the optimal chemisorption toward polysulfides (LiPSs) for boosting polysulfide conversion is a promising way to the efficient Li–S batteries but filled with challenges. Herein, a Co/CoS2 heterostructure is elaborately built to tuning d‐orbital electronic structure of CoS2 for a high‐performance electrocatalyst. Theoretical simulations first evidence that Co metal as the electron donator can form a built‐in electric field with CoS2 and downshift the d‐band center, leading to the well‐optimized adsorption strength for lithium polysulfides on CoS2, thus contributing a favorable way for expediting the redox reaction kinetics of LiPSs. As verification of prediction, a Co/CoS2 heterostructure implanted in porous hollow N, S co‐doped carbon nanocage (Co/CoS2@NSC) is designed to realize the electronic configuration regulation and promote the electrochemical performance. Consequently, the batteries assembled with Co/CoS2@NSC cathode display an outstanding specific capacity and an admirable cycling property as well as a salient property of 8.25 mAh cm−2 under 8.18 mg cm−2. The DFT calculation also reveals the synergistic effect of N, S co‐doping for enhancing polysulfide adsorption as well as the detriment of excessive sulfur doping.