Lithium-sulfur　batteries　(LSBs)　have　become　one　of　the　most　promising　candidates　for　next-generation　energy　storage　systems　owing　to　their　high　theoretical　energy　density,　environmental　friendliness,　and　cost　effectiveness.　However,　real-word　applications　are　seriously　restricted　by　an　undesirable　shuttle　effect　and　Li　dendrite　formation.　In　essence,　uncontrollable　anion　transport　is　a　key　factor　that　causes　both　polysulfide　shuttling　and　dendrite　formation,　which　creates　the　possibility　of　simultaneously　addressing　the　two　critical　issues　in　LSBs.　An　effective　strategy　to　control　anion　transport　is　the　construction　of　cation-selective　separators.　Significant　progress　has　been　achieved　in　the　inhibition　of　the　shuttle　effect,　whereas　addressing　the　problem　of　Li　dendrite　formation　by　utilizing　a　cation-selective　separator　is　still　under　way.　From　this　viewpoint,　this　Review　analyzes　critical　issues　with　regard　to　the　shuttle　effect　and　Li　dendrite　formation　caused　by　uncontrollable　anion　transport,　based　on　which　roles　and　advantages　of　cation-selective　separators　toward　high-performance　LSBs　are　presented.　According　to　the　separator-construction　principle,　the　latest　advances　and　progress　in　cation-selective　separators　in　inhibiting　the　shuttle　effect　and　Li　dendrite　formation　are　reviewed　in　detail.　Finally,　some　challenges　and　prospects　are　proposed　for　the　future　development　of　cation-selective　separators.　This　Review　is　anticipated　to　provide　a　new　perspective　for　simultaneously　addressing　the　two　critical　issues　in　LSBs.