Due to the broad application prospects of optoelectronic devices and microwave devices at high temperature and power, the process of Metal Organic Chemical Vapor Deposition (MOCVD) of AlGaN of the key material AlGaN has been extensively researched in the past 30 years. In order to enhance the quality of AlGaN layers, researchers continuously analyzed their growth mechanism and optimized the growth process through experimental and theoretical studies. In this work, based on reviewing previous studies, we summarize the research progress for AlGaN grown by MOCVD and discuss the existing problems and future research priorities.