A large number of shoal groups form and obstruct navigation in the Jialing River channel from Caojie to the estuary during the dry season. The construction of the Three Gorges Reservoir area further adds to the complexity of the flow and sediment variation of this reach. Under the influence of topographic changes year by year，the effect of channel regulation fails to meet the standards of the planned channel maintenance dimensions. To solve the shoal-induced navigation obstruction problem of the long reach below the hydropower station，this paper analyzes the influence of the backwater in the Three Gorges Reservoir area on the channel dimensions of this reach by two-dimensional hydrodynamic numerical simulation. Then，it obtains the distribution characteristics of the navigation-obstructing shoals in the Jialing River estuary channel under different water levels and proposes the minimum flow requirement of the maintenance dimensions and the corresponding guarantee rate for each key shoal section. The results show that the water levels of different shoal sections of the Jialing River reach from Caojie to the estuary vary greatly under the same flow and that the problem of shoal-induced navigation obstruction is prominent at present. The minimum discharge that meets the requirement of the Class-Ⅲ channel dimensions is about 1 620 m3/s under the current topographic conditions.