Abstract: Objective To analyze the current status and epidemiological trends of the disease burden of gastric cancer among adolescents and young adults (AYA) in China, so as to provide a basis for formulating public health policies and reducing the disease burden. Methods Epidemiological data on gastric cancer among AYA in China from 1990 to 2021 were retrieved from the Global Burden of Disease (GBD) 2021 database. The epidemiological status and changing trends of gastric cancer among AYA in China were described and analyzed. Additionally, the incidence and mortality trends of gastric cancer among AYA from 2022 to 2050 were predicted using the Autoregressive Integrated Moving Average (ARIMA) model. Meanwhile, the influence of relevant risk factors on the disease burden was analyzed. Results In 2021, the incidence and mortality of gastric cancer among AYA in China were 4.12 per 100,000 and 1.86 per 100,000 respectively. Although these figures had decreased compared to those in 1990, they remained higher than the world average. The disease burden in the male population was significantly higher than that in the female population, which might be associated with risk factors such as a high-sodium diet and smoking. The disease burden attributable to a high-sodium diet accounted for 7.39% - 7.87%, and that due to smoking accounted for 6% - 7%. It is projected that the mortality of gastric cancer among female AYA in China may exhibit a downward trend from 2022 to 2050. Conclusion The disease burden of gastric cancer among AYA in China is higher than the world average during the same period, especially notable in the male population. Public health policies such as strengthening tobacco control and promoting a low-sodium diet may contribute to alleviating the disease burden of gastric cancer among AYA.