<p>Silk fibroin hydrogels frequently exhibit insufficient mechanical strength for biomedical applications. Conventional enhancement strategies often rely on toxic crosslinkers or nondegradable components, thereby compromising biocompatibility and biodegradability. Recently emerged organic solvent-based methods represent an advance, but their associated environmental toxicity remains a concern. In this work, we present a novel thermal oscillation strategy for fabricating high-strength silk fibroin hydrogels exclusively from all-aqueous silk fibroin solutions, eliminating the need for toxic chemicals or non-degradable materials. The resulting hydrogels exhibit outstanding mechanical properties, tensile strength of 2.6 MPa, elongation rate of 152.6%, and toughness of 3.0 MJ/m³, which not only surpass the organic solvent-derived silk fibroin hydrogels but also rival the dual-crosslinked, double-networked or composite systems. The silk fibroin hydrogels also exhibit a minimal swelling ratio, outstanding long-term integrity, and excellent biocompatibility. The robust, biocompatible, and biodegradable silk fibroin hydrogels are promising for biomedical applications such as load-bearing tissue scaffolds, long-term implantable drug delivery systems, and durable wound dressings.</p>