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 Krstulovic-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.