In this study, we analyzed the changes of G-17 and ALDH1 levels in gastric juice of 126 patients treated at the Second People’s Hospital of Hefei from March 2023 to March 2024, and explored the diagnostic value of ALDH1 and G-17 levels in gastric juice for gastric cancer and their potential role in the occurrence and development of gastric cancer. Here, ALDH1A1 is linked to gastric cancer.