With　the　growing　severe　challenges　of　the　climate　change,　improving　low-carbon　technical　efficiency　(LTE)　is　considered　as　the　most　important　way　to　facilitate　the　low-carbon　development.　Whether　or　not　China＇s　carbon　emission　trading　(CET)　can　facilitate　the　LTE　deserves　deep　exploration.　Through　the　introduction　of　a　more　scientific　semi-disposability　assumption　for　undesirable　output,　this　paper　first　calculates　China＇s　provincial　LTE　based　on　a　non-radial　and　non-oriented　data　envelopment　analysis　(DEA)　method　and　analyses　the　reasons　for　inefficiency.　Furthermore,　we　explore　the　impacts　and　mechanisms　of　CET　on　the　LTE　using　augmented　difference　in　differences　(augmented　DID)　model.　The　results　show　that　China＇s　provincial　LTE　is　not　satisfactory　which　presents　a　downward　trend　after　experiencing　a　transient　rise.　The　insufficient　low　carbon　innovation　output　is　the　crucial　impeding　the　LTE.　The　implement　the　CET　pilots　has　improved　the　LTE　and　the　promotion　effect　are　mainly　through　strengthening　innovation　support　and　capital　concentration,　while　the　mediating　effects　of　innovation　synergy　degree　and　talents　concentration　are　not　significant.　Therefore,　it　is　essential　for　the　Chinese　government　to　push　forward　the　scientific　construction　of　national　carbon　trading　market　rather　than　increase　the　inputs　blindly,　so　as　to　stimulate　the　innovative　vitality　of　enterprises　as　innovation　subjects.　(C)　2021　Institution　of　Chemical　Engineers.　Published　by　Elsevier　B.V.　All　rights　reserved.