Conductive hydrogels are a new type of material with bionic and electrochemical properties, and their good biocompatibility, flexibility and conductivity make them widely used in flexible sensors, artificial intelligence and other fields. The main classifications of conductive hydrogels are summarized, with a focus on applications in strain sensors, friction nanogenerators, supercapacitors and bioelectronic devices, followed by a summary of current problems and shortcomings and an outlook on future developments.