This paper analyzes the dimension of navigation,the height above water of the navigable vessels,navigable water level,navigation safety and difficulty of bridge reconstruction in the reconstruction project for enhancing the level of inland restricted channels in Hangzhou-Jiaxing-Huzhou plain of the Yangtze River Delta,and proposes the scheme for the bridge demolition and construction project & measures to guarantee the navigation safety,which may serve as reference for similar transformation projects of channels and bridges.