The Jingle Canal in Jingyuan County of Gansu Province is diverted from the south bank of the Yellow River in Lujiazui of Wulan Town with an actual irrigation area of 33.53 km2，with a history of more than 500 years. The Yellow River has a large amount of sediment carried by water，causing serious siltation in the downstream river course and inverted siphon. Aiming at this problem，we plan to move the original water intake up to 3 km，and divert water into the city after sand settles. Through the establishment of a sedimentation basin mathematical model，we combine with the various factors such as water flow，sediment content，and sediment particle gradation，research the sedimentation efficiency，annual sedimentation thickness and flow field distribution of the sedimentation basin，and compare and analyze two types of entrance sedimentation basin schemes. The results show that it is feasible for the calculation of the MIKE21 sediment transport model. The sedimentation effect of the narrow entrance of the sedimentation basin is better than that of the square entrance，flow field distribution is better，and the entrance door is not easy for blockage.