The　operation　of　lithium-ion　battery　(LIB)　at　low　ambient　temperature　leads　to　voltage　drop　and　capacity　attenuation.　Thus,　an　effective　thermal　management　system　(TMS)　is　necessary　to　preheat　the　LIB　at　low　ambient　temperature.　In　this　study,　a　preheating　TMS　for　LIB　based　on　U-shaped　micro　heat　pipe　array　(MHPA)　is　proposed.　The　preheating　performance　of　the　TMS　based　on　U-shaped　MHPA　is　analyzed　through　the　experiments　of　heat　pipe　(HP)　module　covered　and　not　covered　with　thermal　insulation　materials　(TIMs)　and　the　experiments　of　different　electric　heating　powers.　Results　show　that　after　the　TIMs　are　covered,　the　temperature　rise　rate　of　the　HP　module　in　the　preheating　condition　is　increased　by　386%,　and　the　battery　can　be　preheated　from　-20　?　to　0　?　in　26　min　under　32　W　electric　heating.　These　findings　prove　that　the　TMS　has　excellent　preheating　performance.　Moreover,　the　temperature　rise　rate　of　the　HP　module　increases　only　by　9%　under　1C　charge　and　discharge　after　the　TIMs　are　covered,　proving　that　the　preheating　function　of　the　TMS　based　on　U-shaped　MHPA　does　not　interfere　with　the　cooling　function.　Thus,　this　study　provides　guidance　for　the　practical　application　of　TMS.　(C)　2022　Elsevier　Ltd.　All　rights　reserved.