The transparent AlON ceramics have attracted a growing investigation and application in the commercial and military fields, such as infrared and visible windows, domes, and transparent armors. Up to now, although great progress has been reported, such as the improved methods, new sintering additives, and fresh explored applications, a systematic and targeted summary is still lacking. In addition, there are some unsolved problems and challenges of the AlON ceramics, which hinder their commercial promotion and application. In this review, we introduce various preparation methods of AlON ceramics, including high temperature solid-state reaction, carbonization based on Al₂O₃, chemical vapor deposition, and sol-gel method, and thoroughly provide contrastive analysis of their advantages and disadvantages. Furthermore, we also give an insight into the transparency, sintering additives, and sintering technologies of AlON ceramics. At last, the challenges and prospects of AlON ceramics are discussed as well.