Background: SQSTM1/p62 is an autophagy-related receptor protein that participates in regulating tumorigenesis and multiple signaling pathways. Gastric cancer is a common tumor in the digestive tract and continues to pose a significant threat to human health. Therefore, this study aims to investigate the impact of p62 on gastric cancer. Methods: Immunohistochemistry and Western blotting were employed to assess the expression level of the p62 protein in gastric cancer tissues and its correlation with prognosis. Subsequently, in vitro cell experiments were conducted to determine the role of p62 in gastric cancer cell proliferation, migration, and metastasis. Result: The expression of p62 in gastric cancer tissues was significantly higher than in normal tissues. The expression of p62 was positively correlated with poor prognosis in gastric cancer patients. In vitro cell experiments indicated that p62 promotes gastric cancer cell proliferation and migration. Mechanistically, elevated p62 expression induced epithelial-mesenchymal transition (EMT), leading to upregulation of E-cadherin and downregulation of N-cadherin and vimentin. Conclusion: This study provides novel and robust evidence for the mechanism by which elevated p62 expression promotes the progression of gastric cancer. It offers promising therapeutic targets for anti-tumor treatment strategies in gastric cancer patients.