Soil structure and stability can be affected by wetting and drying cycles. Adding poly‐γ‐glutamic acid (γ‐PGA) to soil can improve water retention and plant growth. In this study, different amounts of γ‐PGA were added to sandy and loam soils, and the impact on soil structure and stability under wetting–drying cycles was investigated. Results showed that γ‐PGA increased soil stability and pore size, with certain differences between sandy and loam soils. The number of wetting–drying cycles also influenced soil porosity and pore connectivity. Overall, the study found that soil pore characteristics play a significant role in soil stability when amended with γ‐PGA during wetting–drying cycles.