For　lithium　metal　batteries　(LMBs),　the　elevated　operating　temperature　results　in　severe　capacity　fading　and　safety　issues　due　to　unstable　electrode-electrolyte　interphases　and　electrolyte　solvation　structures.　Therefore,　it　is　crucial　to　construct　advanced　electrolytes　capable　of　tolerating　harsh　environments　to　ensure　stable　LMBs.　Here,　we　proposed　a　stable　localized　high-concentration　electrolyte　(LHCE)　by　introducing　the　highly　solvating　power　solvent　diethylene　glycol　dimethyl　ether　(DGDME).　Computational　and　experimental　evidence　discloses　that　the　original　DGDME-LHCE　shows　favorable　features　for　high-temperature　LMBs,　including　high　Li+-binding　stability,　electro-oxidation　resistance,　thermal　stability,　and　nonflammability.　The　tailored　solvated　sheath　structure　achieves　the　preferred　decomposition　of　anions,　inducing　the　stable　(cathode　and　Li　anode)/interphases　simultaneously,　which　enables　a　homogeneous　Li　plating-stripping　behavior　on　the　anode　side　and　a　high-voltage　tolerance　on　the　cathode　side.　For　the　Li||Li　cells　coupled　with　DGDME-LHCE,　they　showcase　outstanding　reversibility　(a　long　lifespan　of　exceeding　1900　h).　We　demonstrate　exceptional　cyclic　stability　(∼95.59%,　250　cycles),　high　Coulombic　efficiency　(＞99.88%),　and　impressive　high-voltage　(4.5　V)　and　high-temperature　(60　°C)　performances　in　Li||NCM523　cells　using　DGDME-LHCE.　Our　advances　shed　light　on　an　encouraging　ether　electrolyte　tactic　for　the　Li-metal　batteries　confronted　with　stringent　high-temperature　challenges.　©　2023　American　Chemical　Society.