Lithium-ion　batteries　(LIBs)　are　momentous　energy　storage　devices,　which　have　been　rapidly　developed　due　to　their　high　energy　density,　long　lifetime,　and　low　self-discharge　rate.　However,　the　frequent　occurrence　of　fire　accidents　in　laptops,　electric　vehicles,　and　mobile　phones　caused　by　thermal　runaway　of　the　inside　batteries　constantly　reminds　us　of　the　urgency　in　pursuing　high-safety　LIBs　with　high　performance.　To　this　end,　this　Review　surveyed　the　state-of-the-art　developments　of　high-temperature-resistant　separators　for　highly　safe　LIBs　with　excellent　electrochemical　performance.　Firstly,　the　basic　properties　of　separators　(e.　g.,　thickness,　porosity,　pore　size,　wettability,　mechanical　strength,　and　thermal　stability)　in　constructing　commercialized　LIBs　were　introduced.　Secondly,　the　working　mechanisms　of　advanced　separators　with　different　melting　points　acting　in　the　thermal　runaway　stage　were　discussed　in　terms　of　improving　battery　safety.　Thirdly,　rational　design　strategies　for　constructing　high-temperature-resistant　separators　for　LIBs　with　high　safety　were　summarized　and　discussed,　including　graft　modification,　blend　modification,　and　multilayer　composite　modification　strategies.　Finally,　the　current　obstacles　and　future　research　directions　in　the　field　of　high-temperature-resistant　separators　were　highlighted.　These　design　ideas　are　expected　to　be　applied　to　other　types　of　high-temperature-resistant　energy　storage　systems　working　under　extreme　conditions.　©　2022　Wiley-VCH　GmbH.