The poor stability of flavor during shelf life has been one of the main factors restricting the development of green tea beverages. Therefore, in order to improve the flavor stability of green tea beverage during shelf life, the changes of the sensory quality and the main quality chemical composition of green tea beverages supplemented with different sugars such as sucrose, maltose, fructose, and glucose during high temperature sterilization conditions (135℃、15s) and storage process (4℃ and 38℃, 28d) were analyzed, and the potential mechanism was also discussed. The results showed that green tea beverages underwent significant deterioration in flavor quality during high-temperature sterilization and storage process, and supplementing with different sugars helped to increase the quality stability of green tea beverages. The addition of sucrose in green tea beverages was more stable in sensory quality and appearance color and the addition of sucrose and maltose in green tea beverages was more conductive to maintaining the stability of flavor and main flavor components. Based on the analysis of flavor change mechanism of green tea beverages, we found that sucrose, maltose, fructose and glucose had protective effect on EGCG under the condition of high temperature treatment, and maltose had better protective effect. In summary, adding sucrose and maltose can improve flavor stability of green tea beverages.