Abstract: In order to explore the variation law of sediment content and vertical distribution law of suspended sediment along the sand-carrying flow of the Yellow River Diversion Irrigation Project, deduce the critical non silting velocity of harmful sediment suspension in the first project was calculated. The measures and methods to reduce the introduction of harmful sediment were elucidated, so as to improve the utilization efficiency of water transportation and distribution. Taking Zuncun Irrigation District in Shanxi Province as the main research object, the sediment content and settling velocity were analyzed by monitoring the water samples of the Yellow River which taken from May to July 2019, the data of working conditions, section velocity, water depth and water surface width. The particle size gradation was analyzed by using the Malvern Mastersizer 3000 instrument. The formulas of sand-carrying capacity and uplifting velocity applied to the first junction of Zuncun Irrigation District were modified. The results show that there is a positive correlation between sediment content and inflow conditions. The sediment particle size of the Yellow River sediment in Zuncun Irrigation District is mainly 0.006-0.200 mm. The siltation in Zuncun Irrigation District is closely related to the velocity and particle size of the Yellow River estuary. It is suggested to increase the water delivery distance of the Yellow River estuary before the pump, control the flow rate at about 0.30 m/s, and clear the silt at the inlet. The main channel is scoured regularly at a flow velocity that larger than 2.06 m/s. In actual operation, the wor-king condition of single unit should be controlled at about 7.50 m~3/s to reduce the introduction of harmful sediment. The flow velocity in the main channel should be controlled at about 0.42 m/s to achieve the highest water delivery and distribution efficiency.