Abstract: The construction of Gulonggou Bridge, Hanwulagou Bridge, Qiandamen Bridge, Qianli Temple Bridge, Hulestai Bridge, Ulanbulun Bridge and roads have improved the trunk road network of the Inner Mongolia Autonomous Region and promoted the development of roads in the entire Bayan Nur City. This article conducts a comprehensive analysis of the hydrological characteristics, scour calculations and backflow calculations near the six bridges. The six bridges met the local planning requirements, and the design met the overall requirements and remediation goals of the local water plan, and will not cause any important impact on the implementation of the later water plan. The designed flood standard for the bridges is once in 100 years, and the planned flood standard for the river section where the corresponding bridgse is located is once in 10 years, which meets the existing flood standards. The construction height and affected length of the bridges project are small, the scope and extent of the impact are low, and the construction basically does not affect the safety of river floods.