In flood season,between Three Gorges Dam and Gezhouba Dam,the“four beaches,one bend and one pass”of which flow is large,fast and disorderly,and the navigable flow condition is poor.On the basis of the plan of “reef blasting+slag cleaning+ dumping and filling in deep bay”of Liantuo section waterway regulation project,it is verified that whether the project has reached the expected regulation target through prototype hydrological observation before and after and actual ship seaworthiness test after regulation.The effect of engineering regulation is analyzed by observing the changes of surface gradient,water depth and surface velocity in the test reach,and then 3,000-ton and 5,000-ton class fully loaded ships are selected as test ships to carry out real ship seaworthiness tests.The test ships sail on and off the designed route,and the test ships' sailing track,shore speed,drift angle and other sailing indicators and sailing state are measured in real time.At the same time,the results of the prototype hydrology observation and the ship trial in Liantuo section are compared and analyzed combined with the measured data before and after the renovation project,and the seaworthiness performance is analyzed.The results show that the navigable flow conditions and ship navigation conditions of the river reach have been significantly improved after the implementation of the project,and the expected regulation target of the project have been achieved.