Polymer　electrolyte　has　been　considered　to　eliminate　the　safety　issue　that　caused　by　the　lithium　dendrite　growth　in　the　liquid　electrolyte　for　the　high-energy　lithium　metal　battery.　However,　the　practical　applications　of　polymer　electrolyte　are　still　impeded　by　the　low　Li　ionic　conductivity,　weak　interfacial　compatibility,　low　thermal　stability　and　narrow　electrochemical　window.　In　this　study,　we　have　proposed　a　novel　modified　silylterminated　polyether　based　polymer　electrolyte　by　a　cross-linking　fabrication　method.　With　a　three-dimensional　network　structure,　the　amorphous　polymer　electrolyte　has　high　ionic　conductivity　(similar　to　0.36　mS　cm(-1))　at　room　temperature,　much　higher　thermal　stability　(T-m　=　379　degrees　C),　high　lithium　ion　transference　number　(similar　to　0.65),　stable　electrochemical　window　up　to　5.0　V　(vs.　Li+/Li)　and　an　excellent　compatibility　to　the　electrode.　With　LiFePO4　cathode　and　this　polymer　electrolyte,　the　lithium　metal　battery　delivers　the　high　specific　capacity　of　similar　to　130　mA　h　g(-1)　at　1　C　rate　over　300　cycles,　and　similar　to　105　mA　h　g(-1)　at　3　C　rate　with　a　superb　cycling　stability　over　600　cycles　at　room　temperature.　We　believe　that　this　polymer　electrolyte　is　a　promising　candidate　for　the　practical　applications　and　brings　a　new　way　to　develop　the　high　performance　electrolyte　for　the　lithium　metal　battery.