The transport process of sediment particulates and particulate phosphorus (PP) in shallow lakes is crucial for sediment deposition and water quality evolution. Aiming at the unclear issue regarding the transport mechanism of particulates and particulate phosphorus in Lake Taihu and their contribution to sediment deposition, this study investigated the overall balance, transport characteristics, and deposition patterns of suspended solids (SS) and particulate phosphorus entering and exiting Lake Taihu. The research was conducted through a one-year monitoring of inflow and outflow rivers, combined with a one-month whole-lake sampling and particle size classification analysis, and the application of the flux balance method. The results indicated that the in-lake sediment accumulation of particulates in Lake Taihu was significant, and the retention of phosphorus with particulates was prominent. In 2021, the net inflow of SS into Lake Taihu was approximately 400,000 tons, corresponding to a sediment volume of about 550,000 m3, with a deposition rate of 0.35 millimeters per year. During the same period, the net retention of PP was 989 tons, and approximately 73% of the inflowing PP entered Lake Taihu along with particulates, which revealed that particulate sedimentation was identified as the main pathway for phosphorus accumulation. There were significant differences in the particle size of particulates and the occurrence forms of phosphorus between the inflow and outflow of Lake Taihu. The inflowing particulates were mainly 20-50 μm in size, while the outflowing ones were mainly 0.45-10 μm. Moreover, the particulates of 10-20 μm carried more than 80% of PP. The hydrodynamic process in the lake had a significant impact on the spatial distribution of particulates and PP. The particulates in Lake Taihu showed a distribution pattern of "high in the west and low in the east", while particulate phosphorus exhibited a characteristic of "high in the northwest and low in the southeast.