Combining channel service conditions of the existing project,according to the achievements of investigation and research in native and foreign,Inland river navigation specification,Code for design of general layout of sea ports,we design the floating channel in the limited water area and large immersed tube,obtain the key technical parameters of the width and depth of the channel design,and apply the technique in selection of floating channel of the Hong Kong-Zhuhai-Macao Bridge immersed tube tunnel.According to measurement and analysis of the immersed in the project,we obtain the track line of the immersed floating.The analysis and results are verified by practical application,and satisfy the engineering construction requirements.