Aluminum titanate was in-situ synthesized by using industrial waste-residue in the aluminum factory and TiO2 as the main raw materials and the influence of different reaction temperatures on the purity and microstructures of synthesized products were mainly discussed. The obtained Al2TiO5 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and relevant analytical software. The results show that elevating the sintering temperature can increase the content of aluminum titanate; and at 1420 ℃, it reaches the highest in the synthesized ceramic. When the sintering temperature continues to increase, the produced aluminum titanate will decompose resulting in the drop of its content. Therefore, the optimum sintering temperature of in-situ synthesis of aluminum titanate is determined as 1420 ℃, at which the grains of aluminum titanate grow completely, the purity of aluminum titanate is 89.3wt%., the highest density is 2.75 g/cm3, and the porosity is 9%. Aluminum titanate was in-situ synthesized by using industrial waste-residue in the aluminum factory and TiO2 as the main raw materials and the influence of different reaction temperatures on the purity and microstructures of synthesized products were discussed in detail. The Al2TiO5 was characterized by X The results show that elevating the sintering temperature can increase the content of aluminum titanate; and at 1420 ° C, it reaches the highest in the synthesized ceramic. When the sintering temperature continues to increase, the produced aluminum titanate will decompose resulting in the drop of its content. the purity of aluminum titanate is 89.3 wt%, the highest density is 2.75 g / cm3, and the porosity is 9%.