Breast cancer (BRCA) is one of the major threats to women's health worldwide. This study focuses on the roles of sorbin and SH3 domain‐containing protein 2 (SORBS2) protein and microRNA‐138‐5p in the progression of BRCA, analyzing their regulatory effects on cancer cell proliferation, cell cycle, and migration ability. Using bioinformatics tools and experimental methods, the study found that SORBS2 is commonly underexpressed in BRCA. Additionally, it demonstrated that microRNA‐138‐5p can significantly inhibit tumor growth by suppressing SORBS2 expression, providing new molecular targets for BRCA treatment.