Electro-conductive hydrogel is a new composite hydrogel with high electrical conductivity, extraordinary mechanical properties, and controllability. It can be equipped with specific materials to obtain specific properties, which has attracted considerable research attention due to its wide range of application as a biomaterial in the biomedical engineering field. It can be used as a patch to promote healing and as a dressing for burns and pressure wounds. In pharmaceutical science, it is widely studied as a carrier of targeted and quantitative drug release. In surgery, it can serve as a cell scaffold for implantable therapy. Currently, increasing research is focusing on the development of sensors as simulated skin for robots, as well as in health monitors for human activity and well-being. In this review, we summarize the classification and selection of conductive mediums, natural polymer hydrogel matrices, and the application of electro-conductive hydrogels in the fields of bioengineering and biomedicine. We delve into the properties of different conductive mediums and the principle of combining different hydrogel matrices and discuss the advantages and disadvantages of emerging composite hydrogels. Our focus extends to the forefront of conductive hydrogel research in various fields, while also elucidating the current problems and challenges in terms of performance integration, preparation process and practical applications.