Abstract: Microplastic pollution in the marine environment is a common global problem, and Pearl River Estuary is a typical area of marine microplastic pollution in China. In order to explore the spatial distribution and migration mechanism of microplastics in Pearl River Estuary, the authors processed and analyzed surface sediment samples from 55 stations in the southern Pearl River Estuary. And the microplastics in the samples were identified and counted. The research results are as follows. (1) The microplastics abundance in the study area varied in the range of 0~47.77 items/kg, with uneven spatial distribution, and it was enriched in the sea area from Modaomen to Daji Bay and from Xiangzhou Bay to Guishan Island. The microplastics abundance was at a low level compared with other waters in the South China Sea. (2) The sources of microplastics in the study area were mainly human activities on both sides of the river. Driven by the dual drive of tidal flow and runoff, the microplastics carried in the water body of the Modaomen channel were unloaded and accumulated in the sea area from Modaomen to Dajiwan Estuary. While the microplastics carried by the water body of the Pearl River Estuary were unloaded and accumulated in the sea area from Xiangzhou Bay to Guishan Island. The results of this study could provide some references for the study of environmental pollution in China's coastal waters, and also provide some data for monitoring microplastics in the marine resources in the southern areas of China.