Living organisms, from plants to animals, have inspired and guided the design and fabrication of polymeric hydrogels with biomimetic morphology, shape deformation and actuation behavior. However, the existing polymeric hydrogels are fragile and vulnerable, which seriously hindered their further applications. Therefore,  endowing hydrogels with biomimetic self-growth property and regenerating the macroscopic shape of hydrogels after suffering huge damage are highly desirable for the next generation of adaptive biomimetic hydrogels. Inspired by the tail regeneration of gecko, we herein reported an efficient and universal strategy of interfacial diffusion polymerization (IDP), which could regenerate the polymeric layer at a solid-liquid interface, thereby growing new hydrogels upon the existing hydrogels layers. Through changing the solvent viscosity and/or monomer type of hydrogel precursor, diverse new hydrogels are regenerated to endow the initial hydrogels with additional fluorescent functions and/or actuating properties. Due to the high efficiency and universality of IDP, an injured hydrogel actuator can be repaired, regenerated, and recovered to the initial condition even after suffering severe damage such as cutting or piercing. We believe that the regeneration strategy of polymeric hydrogels will inspire the design of biomimetic materials and motivate the fabrication of next generation of soft robots with adaptive and multi-functional properties.