<p>Metal ions are involved in many biological functions such as enzyme catalysis, signal transduction and gene expression regulation in biological system. They play multiple roles in the pathogenesis and immune escape mechanism of gastric cancer(GC). This review begins by outlining the fundamental biological roles of metal ions, highlighting its significance in tumor development. We focus on elucidating how metal ions modulate the gastric cancer immune landscape by regulating immune cell functions, and participating in specific signaling pathways. Additionally, the potential of metal ion interference as an emerging therapeutic strategy for tumors is discussed, along with the prospects for applying metal-based nanomaterials in the treatment of gastric cancer. Additionally, we discuss the crosstalk between ferroptosis and cuproptosis mediated by metal ions, which provides a novel perspective for understanding metal ion-dependent tumor cell death. The potential of metal ion interference as an emerging therapeutic strategy and the application prospects of metal-based nanomaterials in gastric cancer treatment are summarized. Finally, we point out key future research needs, including clarifying the dynamics of metal ions in the gastric cancer microenvironment, standardizing metal-related biomarkers for clinical stratification, and optimizing the safety and targeting of metal-based therapies. This review comprehensively summarizes the regulatory roles and mechanisms of metal ions in the gastric cancer immune microenvironment, offering theoretical support for the development of precision therapeutic strategies targeting metal ion homeostasis.</p>