Black garlic is produced through the fermentation of fresh garlic under conditions of high temperature and humidity, wherein various chemical reactions occur, gradually diminishing the pungent odor associated with garlic and imparting the distinctive sweet and sour flavor characteristic of black garlic. This article reviews the changes in chemical components and flavor substances during the processing of black garlic, discusses the key factors that influence the evolution of its aroma profile, and analyzes the flavor characteristics of black garlic.