Abstract: A high-calcium fly ash geopolymer cementitious material was prepared by using high-calcium fly ash from a power plant in Xinjiang and sodium silicate as an alkali activator. This paper studied the effects of water glass content, water-binder ratio and water glass modulus on the compressive strength of high-calcium fly ash geopolymer and the durability of the prepared polymer materials. The results showed that the optimal conditions are as follows:high calcium fly ash of 100%, sodium silicate content of 8% with modulus of 1.1 and water/binder ratio of 0.37. The strength values of the prepared geopolymer samples after 3, 7 and 28 days were 23.0 MPa and 33.3 MPa, and 51.7 MPa, respectively. Durability studies showed that the strength value of geopolymers could reach 83.3 MPa after 120 days, which was greater than that of the 42.5 cement mortar.