Applications　of　Li-S　batteries　are　primarily　hindered　by　shuttling　effect,　poor　electronic　conductivity　of　sulfur　and　inactive　decomposition　of　low-order　lithium　polysulfide　(LiPS).　To　solve　these　problems,　the　anchoring　and　electrocatalysis　properties　of　two-dimensional　transition　metal　boride　(MBene)　have　been　extensively　studied　to　provide　general　design　principles　for　enhanced　electrochemical　performance　in　Li-S　batteries.　Our　results　show　that　direct　application　of　bare　Mo2B2　MBene　in　Li-S　battery　gives　rise　to　the　decomposition　of　high-order　LiPSs,　which　originates　from　the　excessively　strong　binding　strength　between　S　atoms　and　surface　Mo　atoms.　Then,　we　highlight　that　surface　functionalization　on　Mo2B2　MBene　possesses　suitable　anchoring　performance　to　suppress　the　shuttling　effect.　Meanwhile,　owing　to　the　excellent　electronic　conductivity　even　after　the　adsorption　of　LiPS,　the　functionalized　MBenes　effectively　stimulate　the　redox　electrochemistry　in　Li-S　battery.　Finally,　accompanied　with　omnidirectional　fast　diffusion　of　Li　atom,　the　functionalized　MBene　exhibits　superior　electrocatalysis　activity　for　Li2S　decomposition　with　ultra-low　diffusion　(0.191　eV)　and　decomposition　(0.441　eV)　barriers,　improving　the　capability　and　coulombic　efficiency　of　Li-S　batteries.　Our　findings　pioneer　the　application　of　MBenes　as　anchoring　and　electrocatalysis　materials　for　Li-S　batteries　and　provide　a　developed　insight　on　the　design　of　high-performance　Li-S　battery　cathodes.