Abstract: The Wanhe River is the largest tributary to Changjiang River Anhui Province section.Its estuary section is affected by both the upstream inflow and the backwater of the Changjiang River, so the river regime is complex and changeable.In view of the special hydrological situation of the section, the water level-flow relationship between the Wanhe River and the Changjiang River was systematically studied, and the recent flood and drought disaster scenarios were analyzed.The evolution characteristics of this section were systematically analyzed from the aspects of river plane shape, erosion and deposition variation of beaches and channels, vertical and horizontal variation of the confluence waters.By establishing a two-dimensional hydrodynamic mathematical model, the flow characteristics of this section under flood and drought conditions were also studied.The results show that when the water level of Anqing Station is above 10.40 m, the water level of the Yangtze River is the dominant factor affecting the water level of the Wanhe River estuary section.While the water level of Anqing Station is lower than 10.40 m, the upstream inflow becomes the major affecting factor.Since 2008, the channel from Balihu to the estuary of the Wanhe River has been slightly scoured, and a large area of beach has been silted up, with average siltation thickness of 1~2 m and up to 3~4 m in local areas, and the total siltation of the beach is about 58 million m³.During the low flow periods, the water from the Wanhe River tributary into the Changjiang River estuary is poured backward.While during the flood periods, constrained by the backwater effect of the Changjiang River and the dense buildings on the left and right banks, there is a low-velocity recirculation zone in the estuary, which leads to sediment deposition in the recirculation zone and poor flood discharge ability.On this basis, the regulation needs of flood control and drought resistance, shipping development and water resources utilization in this river section are studied and argued.The regulation countermeasures such as building new water conservancy projects, improving dike grade and carrying out channel dredging are put forward to improve the shipping and flood-drought disaster prevention ability of Wanhe River Basin.