Keratin-based hydrogels have shown promise as materials for wastewater remediation, yet their low surface area and poor mechanical performance hindered the practical application. To address these challenges, we developed a bowl-shaped polydopamine-loaded sponge bio-hydrogel (BPSH) with a hierarchical porous structure and high stability. The extruded keratin chains facilitated the formation of three distinct macroporous frameworks, while embedding bowl-shaped polydopamine into the bio-hydrogel significantly enhanced the hierarchical porous structure. This modification introduced various functional groups, such as hydroxyl, amino, and aromatic rings, improving the surface area, porosity, mechanical strength and adsorption capacity of the materials. The BPSH demonstrated selective adsorption of anionic dyes, particularly Congo red (CR), with a remarkable adsorption capacity (Q