α-Al2O3 has important applications in refractories, electronic materials and many other fields. This article first introduces the evaluation index of α-Al2O3 in industrial application and α-Al2O3 phase transition mechanism. Then the article expounds related research progress of the α-Al2O3 preparation, from three aspects that solid phase synthesis, liquid phase synthesis and gas phase synthesis, respectively. The factors which affect the microstructure of α-Al2O3 particles during preparation are discussed, including calcination temperature, mineralizer, pH value and pretreatment conditions. Finally, the lack of research on the nucleation growth mechanism of α-Al2O3 is pointed out, and indicating that a specific nucleation mechanism, the mass production of high purity α-Al2O3 and morphology control technology will be the future research focus and development direction in this field.