The　solubility　and　dissolution　rate　of　gypsum　have　important　effects　on　the　hydration　and　properties　of　anhydrous　calcium　sulfoaluminate.　In　this　paper,　isothermal　calorimeter,　XRD,　TG-DTG　and　other　test　methods　were　used　to　study　the　dissolution　characteristics　of　hemihydrate　gypsum,　dihydrate　gypsum　and　anhydrite　and　their　effects　on　the　hydration　process　of　anhydrous　calcium　sulfoaluminate.　Based　on　Krstulovie-Dabic　and　Kondo　model,　the　kinetic　parameters　of　each　stage　of　hydration　reaction　were　calculated.　The　results　show　that　the　solubility　of　hemihydrate　gypsum,　dihydrate　gypsum　and　anhydrite　in　pure　water　is　2.　74,　2.　30,　2.　38　g/L,　respectively.　The　dissolution　rate　of　hemihydrate　gypsum　is　the　maximum,　followed　by　dihydrate　gypsum,　and　the　minimum　is　anhydrite　(1　h　solubility　is　1.　19　g/L).　The　addition　of　gypsum　shortens　the　induction　period　of　hydration　of　anhydrous　calcium　sulfoaluminate　and　accelerates　the　process　of　hydration,　where　hemihydrate　behaves　most　significantly,　with　the　hydration　heat　curve　having　almost　no　induction　period,　followed　by　dihydrate,　and　anhydrite　having　the　least　effect　on　the　induction　period.　At　the　beginning　of　the　acceleration　period,　the　hydration　rate　constant　from　small　to　large　is　anhydrite　system,　dihydrate　system,　hemihydrate　system.　The　dissolution　rate　and　solubility　of　gypsum　affect　the　formation　process　of　ettringite.　The　gypsum　with　large　dissolution　rate　prompts　the　appearance　of　ettringite　precipitation　at　the　early　stage　of　hydration　and　the　amount　reaches　the　maximum　value　quickly.　And　in　the　same　time,　the　system　with　the　addition　of　gypsum　with　high　solubility　has　a　large　amount　of　ettringite　production.　At　1　h　of　hydration,　the　amount　of　ettringite　produced　in　the　hemihydrate　system　is　about　15.　77%　(mass　fraction)　of　the　total　sample,　13.28%　(mass　fraction)　in　the　dihydrate　system　and　only　3.60%　(mass　fraction)　in　the　anhydrite　system.　©　2023　Authors.　All　rights　reserved.