<p>Simulating biomineralization to induce calcium carbonate precipitation is an emerging cementation technique that offers an effective and environmentally sustainable solution for foundation improvement. However, their durability under environmental stress remains poorly understood, limiting broader engineering applications. This study evaluates the evolution of biomimetic cemented soil’s mechanical properties and pore structures under wet–dry and freeze–thaw cycles, as well as over time, and elucidate key failure mechanisms. Results indicate that both cyclic conditions significantly degrade biomimetic cemented soil strength and alter failure morphology. Wet–dry cycles, in particular, induce mass loss by disrupting calcium carbonate “bridges” between adjacent sand particles, reducing cementation efficiency. This deterioration leads to particle detachment, forming large-volume voids that increase biomimetic cemented soil porosity by up to 12.19% and hydraulic conductivity coefficient by up to 340.98%. In contrast, freeze–thaw cycles generate fine cracks with a high specific surface area, diminishing the dynamic shear modulus of biomimetic cemented soil. Nevertheless, biomimetic cemented soil still exhibits “heavy cementation” behaviors after 20 wet–dry or freeze–thaw cycles. Notably, unlike traditional cementitious materials, due to the stability of calcium carbonate crystals at ambient temperature, biomimetic cemented soil properties remain largely unchanged with aging. This study focused on the changes in mechanical properties and voids characteristics of biomimetic cemented soil, highlighting the durability challenges and provide critical insights into improving biomimetic cemented soil for ground improvement.</p>