Abstract: In this dissertation, the preparation, advantages and application research status of the new inorganic polymer flocculants polyaluminium chloride (PAC) have been summarized. The PAC were prepared respectively by using calcium aluminate and hydrochloric acid, sodium hydroxide and aluminum chloride, calcium aluminate and industrial waste acid as the main raw material, under temperature 72℃. In process of sample preparation, through the add quantity of calcium aluminate, acid concentration and maturation time factor studying show: 14% hydrochloric acid 200ml and 28g calcium aluminates, that is ratio of materials (physical weight): acid (total 100% ) ≈ 1.0, at temperature 72℃, with magnetic stirrer stirring until completely dissolved. The PAC which prepared by maturating 48 hours in 72℃ thermostat has the best performance of flocculation. The results of wastewater treatment show the PAC which prepared by using calcium aluminum and hydrochloric acid as raw material were the best about flocculation effect. At wastewater’s pH = 7.0, flocculation can clarify completely in 5 min, and COD removal rate reaches 60%.