Diabetic patients face an increased risk of developing cataracts, with unclear mechanisms. Our study illuminates these mechanisms by identifying differentially expressed proteins in the lens anterior capsule of diabetic cataract (DC) and age-related cataract patients using quantitative proteomics. We found SH2B1 to be crucial in DC progression. Reduced SH2B1 expression was confirmed through PCR and Western blotting in patient samples, diet-induced obese mice, and high-glucose (HG)-cultured human lens epithelial cells. Under HG conditions, cell proliferation decreased, while migration and apoptosis, alongside changes in Bcl2 and caspase 3 expression, increased. Overexpressing SH2B1 alleviated these changes and influenced the p38 MAPK signaling pathway. This suggests SH2B1 and the p38 MAPK pathway as significant in DC pathogenesis and potential therapeutic targets. Clinically, this could lead to therapies aimed at halting or slowing DC progression.