Abstract: Bio-based conductive hydrogel is a conductive material prepared by introducing biomass material and conductive medium into hydrogel, which is widely used in the field of flexible electronic devices due to its advantages such as good biocompatibility and skin friendliness. This review introduces three common types of bio-based conductive hydrogels, namely, protein-based, polysaccharide-based, and nucleic acid-based, according to the categories of bio-matrix, analyzes the conductive mechanisms of different bio-based materials and their respective unique functions, and introduces the applications of bio-based conductive hydrogels in flexible electronic devices, such as flexible sensors, flexible electrochemical energy storage devices, friction nano-generators, and biomimetic flexible electronic devices, etc., and finally provides a comprehensive overview of the development trend of bio-based conductive hydrogels. Finally, the development trend of bio-based conductive hydrogels is summarised and outlooked.