Triethanolamine　(TEA),as　a　commonused　component　in　cement　concrete　for　early　strength,which　can　significantly　promote　the　development　of　early　strength.　In　recent　years,with　the　rapid　development　of　shotcrete　and　liquid　alkali-free　accelerator,triethanolamine　has　been　widely　used　due　to　its　excellent　early-strength　characteristics.　However,the　performance　of　accelerator　prepared　from　triethanolamine　under　different　conditions　are　not　the　same　or　even　the　opposite.　Its　influence　law　and　action　mechanism　on　early　hydration　of　cement　need　to　be　clarified.　In　this　study,liquid　alkali-free　accelerator　with　different　proportions　of　TEA　was　prepared.　The　influence　of　TEA　in　the　alkali-free　accelerator　on　the　early　hydration　of　cement　was　investigated　in　detail　from　the　aspects　of　setting　time,early　strength,hydration　exothermic　behavior,hydrate　phase　and　thermal　analysis.　The　results　show　that　when　TEA　accounted　for　0.　25%　of　the　mass　of　alkali-free　accelerator,the　setting　time　was　the　shortest,the　initial　setting　was　109　s,the　final　setting　was　324　s,and　the　strength　was　the　highest　at　1　d,reaching　12.　32　MPa,which　meets　the　national　standard　requirements　of　accelerator　for　shotcrete.　TEA　can　accelerate　the　accelerating　effect　of　alkali-free　accelerator　on　early　hydration　of　cement　at　low　dosage,while　it　can　significantly　weaken　and　inhibit　early　hydration　of　cement　at　high　dosage.　In　addition,the　complexation　mechanism　between　TEA　and　aluminum　phase　was　studied　by　means　of　conductivity　and　nuclear　magnetic　hydrogen　spectroscopy,and　the　regulation　mechanism　of　TEA　to　liquid　alkali-free　accelerators　on　the　‘accelerating-inhibiting’early　hydration　of　cement　was　revealed:(ⅰ)when　the　content　of　TEA　is　low,metaaluminate　ions　complex　with　TEA　and　participate　in　accelerating　the　early　hydration　of　C3　A;(ⅱ)high　TEA　content　will　produce　a　large　amount　of　ettringite　and　TEA-Ca　complex,which　will　cover　the　surface　of　C3　A　and　inhibit　hydration.　This　study　systematically　explores　the　influence　and　regulation　mechanism　of　liquid　alkali-free　accelerator　with　different　TEA　contents　on　early　hydration　of　cement,which　provides　an　important　research　basis　and　scientific　guidance　for　the　development　of　high-performance　liquid　alkali-free　accelerator.　©　2023　Cailiao　Daobaoshe/　Materials　Review.　All　rights　reserved.