The further understanding of the fluvial processes in Ningxia and Inner-mongolia reach of Yellow River is got through analysing the scouring and silting evolution of the channel and its flood conveyance capacity change. According to the designed water-sediment conditions of Xiaheyan hydrological station, the scouring and silting variation trend in 2020and 2030was estimated. The analysis indicated that in recent years, sediment transport capacity of the channel was reduced, bankfull discharge of Bayangaole, Sanhuhekou, Zhaojunfen sections had a decreasing trend, river siltation increased and main stream was clogged by tributaries more frequently. Based on the designed water-sediment conditions of Xiaheyan hydrological station, the quantities of water and sediment of Toudaoguai hydrological station and interzone sediment diversion were calculated, and the scouring and silting amount from Xiaheyan to Toudaoguai was estimated by using sediment balance method and considering incoming sediment from tributaries and windblown sand transported into the main stream of Yellow River. The annual average deposition amount of the channel of Ningxia and Inner-mongolia reach will be 78million tons in 2020and 80million tons in 2030.