Accelerator　is　an　indispensable　chemical　admixture　for　sprayed　concrete,　but　there　are　differences　and　controversies　on　the　understanding　of　the　mechanism　of　quick　setting　and　hardening　action.　From　the　perspective　of　the　cement-accelerator-water　system,　the　effects　of　different　types　of　accelerator　on　the　hydration　reaction　characteristics　and　quick　setting/hardening　mechanism　of　the　cement-accelerator-water　system　were　reviewed　and　analyzed.　It　is　clear　that　the　rapid　formation　of　hydrated　sulfoaluminate　hydration　products　in　the　water-filled　pores　is　the　main　reason　for　achieving　quick　setting.　The　crystal　transformation　of　the　ettringite　(AFt)　to　calcium　mono　sulfoaluminate　hydrate　(AFm)　leads　to　an　increase　in　the　porosity　of　the　hardened　structure　and　delays　the　hydration　of　the　silicate　minerals.　That　is　the　reason　why　the　aluminate　accelerator　causes　the　later　strength　reduction　of　sprayed　concrete.　The　chemical　composition　of　cement　has　an　important　influence　on　the　hydration　process　and　setting/hardening　of　the　cement-accelerator-water　system.　The　high　shear　effect　of　the　spraying　process　will　accelerate　the　formation　of　AFm,　inhibite　the　hydration　of　silicate　minerals,　and　have　a　negative　effect　on　the　development　of　sprayed　concrete　strength　with　the　addition　of　alkaline　accelerator.　©　2020　Bulletin　of　the　Chinese　Ceramic　Society　Press.　All　rights　reserved.