Hydrogels have been drawing growing attention as environmentally friendly, high-value sand-fixing agents, though traditional polymer-based types are typically limited by overly flexible molecular chains and unstable network structures. These flaws lead to performance degradation under harsh conditions (e.g., high temperatures, salt-alkali erosion), failing to meet long-term durability demands for desert infrastructure. To address this bottleneck and enable efficient and sustainable cement-free aeolian sand fixation, this study developed a high-strength, erosion-resistant hydrogel sand-fixing agent, stable both in dry environments and under multiple stressors. The introduced methyl groups significantly enhance molecular chain rigidity, endowing sand columns with ultrahigh compressive strength (up to 54.3 MPa, commercial C30 concrete can reach 37.8 MPa). Moreover, these sand columns maintain high stability under extreme conditions. After reaching swelling equilibrium in acid or alkali environments and undergoing drying, their strength can recover to over 50 MPa. As a low-carbon engineering material tailored for desert environments, this work not only exhibits broad application prospects but also provides an innovative solution for desert resource utilization and ecological engineering initiatives.