Abstract: Layered double hydroxide-biochar (LDH-BC) composites, novel biochar-based composite nanomaterials that have been shown to be highly effective in adsorbing pollutants and catalyzing degradation in wastewater treatment. This review provides a thorough and organized overview of the current research on LDH-BC composites, which can be used to inform future studies. The research content provides a summary of the synthesis method of LDH-BC composites, the modification strategy, and the application and mechanism of the composites in wastewater treatment. It is suggested in the outlook section that LDH-BC composites have problems inadequate research such as unclear degradation paths of specific components, less application of composite pollutant systems, and lack of field scale tests. The next step is to explore the above shortages of research further in order to promote the research and application of LDH-BC composites.