Abstract: Covalent organic frameworks (COFs) are an emerging class of porous crystalline materials, demonstrating great potential in environmental applications, owing to the unique merits including good chemical stability, high specific surface area, ordered skeletons and well-defined pores, designable structure, and so on. This paper summarizes the recent progress of COFs in the field of heavy metal ions adsorption, degradation of pollutants in water, and desalination of seawater. Finally, we figure out an outlook about the application prospects of COFs in wastewater treatment.