This paper introduces the pollution status and occurrence characteristics of microplastics in freshwater environment in China, expounds the important role of pretreatment methods such as chemical digestion and qualitative techniques such as spectral analysis in analyzing the pollution characteristics of microplastics, and further studies the toxic effects of microplastics on plankton, benthos, fish and other aquatic organisms. The results show that the situation of microplastic pollution in freshwater of China is serious. It is necessary to study the analytical methods and biological effect and mechanism of microplastics, and strengthen the prevention and control of freshwater as soon as possible.