The　preparation　of　high-efficiency　and　ultra-stable　bifunctional　electrocatalytic　materials　is　of　great　significance　to　the　development　of　sustainable　and　clean　hydrogen　energy　by　water　splitting.　In　this　work,　a　low-cost　and　efficient　bifunctional　Co9S8/2H-WS2　argyrophylla-like　heterostructure　was　purposely　loaded　on　nickel　foam　(Co9S8/2H-WS2@NF)　via　simple　and　feasible　in-suit　electrodeposition　route.　The　Co9S8/2H-WS2@NF　can　achieve　a　current　density　of　10　mA　cm−2　at　an　overpotential　of　57　mV　for　hydrogen　evolution　reaction　(HER)　and　253　mV　for　oxygen　evolution　reaction　(OER)　in　1.0　mol/L　KOH　solution.　Moreover,　only　1.58　V　is　needed　to　achieve　the　overall　water　splitting　at　10　mA　cm−2.　The　optimized　interfacial　electrons　redistribution　that　promoting　the　catalytic　performance　were　proved　by　the　density　functional　theory　(DFT)　calculations.　Therefore,　this　work　provides　new　opportunities　in　promoting　the　performances　of　overall　water　splitting　through　low-cost　bimetallic　sulfide.　©　2021　Wiley-VCH　GmbH