The drift paths of microplastic particles from six main input sources of Taihu Lake were calculated by coupling the environmental fluid dynamics code(EEDC) model with the Lagrangian particle model. The main factors affecting the drift path of microplastic particles were analyzed, and the microplastic pollution probability in Taihu Lake was further assessed. The results show that the location of microplastic input sources and nearby lake current are important factors determining the migration destination of microplastics. The lake bay is the main destination of microplastics in Taihu Lake due to the effect of circulation in the bay. Zhushan Lake and Gonghu Lake receive microplastic particles from their own input sources, as well as microplastic particles from the western and southern coastal areas. Zhushan Lake has the maximum microplastic pollution probability in Taihu Lake, with microplastic particles mainly from the input sources of the its own lake bay and the western coastal area. The microplastic pollution probability in the western coastal area ranks the second place, with microplastic pollution mainly from the input sources of itself and the southern coastal area.