<p>Bionic hydrogels offer significant advantages over conventional counterparts, boasting superior properties like enhanced adhesion, stretchability, conductivity, biocompatibility and versatile functionalities. Their physicochemical resemblance to biological tissues makes bionic hydrogels ideal interfaces for bioelectronic devices. In contrast, conventional hydrogels often exhibit inadequate performance, such as easy detachment, lack of good skin compliance, and inadequate conductivity, failing to meet the rigorous demands of bioelectronic applications. Bionic hydrogels, inspired by biological designs, exhibit exceptional physicochemical characteristics that fulfill diverse criteria for bioelectronic applications, driving the advancement of bioelectronic devices. This review first introduces a variety of materials used in the fabrication of bionic hydrogels, including natural polymers, synthetic polymers, and other materials. Then different mechanisms of hydrogel bionics, are categorized into material bionics, structural bionics, and functional bionics based on their bionic approaches. Subsequently, various applications of bionic hydrogels in the field of bioelectronics were introduced, including physiological signal monitoring, tissue engineering, and human-machine interactions. Lastly, the current development and future prospects of bionic hydrogels in bioelectronic devices are summarized. Hopefully, this comprehensive review could inspire advancements in bionic hydrogels for applications in bioelectronic devices.</p>