Colloid is a mixed multi particle system with particle diameters between 1 nm and 1 μm. The natural aquatic colloids are defined as the sum of the ubiquitous substances in the aquatic environment with "colloidal" form. Due to the specific surface chemistry and long residence time in the environment, colloids play an important role in regulating the speciation, transformation, and fate of trace metals and other pollutions. In this paper, the formation and development of colloids in the research field of water environment were summarized and concluded, and the definition and separation method of natural aquatic colloids were discussed and compared. To better understand the environmental behaviors in water environment, the characteristics, composition of natural aquatic colloids, and the corresponding detection method were summarized in detail. This paper also summarized and concluded the major research findings about the binding interaction between colloids and pollutants, the migration and aggregation of colloids, and its impacts on the transportation and transformation of pollutants. Finally, this paper emphasized that the complex composition and dynamic processes of colloids are innovative to the research of colloids in water environment, and the research methods and thoughts have been outlook for further study on the environmental effects of colloids.