The present paper investigated the effect of mineralizer on the structure and properties of calcium aluminates formation. Calcium aluminates powder was synthesized under high temperature calcination by mixing bauxite, limestone and a certain amount of mineralizer. The product structure, compositional information and spectral properties were carefully characterized by XRD, IR and DTA-TG, and the mineralization mechanism of mineralizer was studied during the process of calcium aluminates preparation. The results showed that calcium aluminates powder could be obtained under lower temperature calcination after adding mineralizer to the raw materials. The main products of the reaction were CaAl10O18 and CaAl2Si2O8 without mineralizer, however, the main products of the reaction were CaAl3BO7 and Ca3Al10O18 with mineralizer, in which Al2O3 could be extracted easily, while CaAl2Si2O8 was reduced greatly in which Al2O3 could not be extracted easily. At the same time, it is easy for calcspar to decompose after adding mineralizer. It is favorable to Al—Si bond break and Al stripping from bauxite .These facts could improve the extraction rate of Al2O3 from raw materials. Also, in the case of adding mineralizer to the raw mixes, the crystal structure and composition are changed, which is beneficial to reducing calcination temperature.