China has very rich resources of anhydrite, and anhydrite resources only in Hanshan of Anhui Province has reached 60 million tons. The development of natural anhydrite as a binding material has important research value in developing low carbon economy and energy conservation. The composition, structure and hydration hardening performance of natural anhydrite were analyzed in this paper. The activity and improvement of the activity of natural anhydrite by adding different activators were studied. Hydrous mechanisms of natural anhydrite were also analyzed. Taking natural anhydrite (Ⅱ type anhydrous gypsum) produced by Hanshan County of Anhui Province as the major raw material, the influences of five kinds of chemical activators（K2SO4, FeSO4·7 H2O, CaO, Na2C2O4 and calcined alum） on the hydration property of natural anhydrite were investigated. The hydration rates of anhydrite with different contents were detected using the gravimetric method. The composition and microstructure of hydrated products of natural anhydrite were characterized by XRD and SEM. The activated mechanism of hydration activity of natural anhydrite was further discussed. The experimental results indicate that the chemical activator the authors used could obviously promote the hydration rate of natural anhydrite, and the crystal microstructure of the hydration and hardened body was also notably improved after doping activator. The natural anhydrate mixed with 5.0% calcined alum had very good activating action on hydraion. 28 days later, the hydration rate reached 74.32%.