The renovation and expansion of the ship lock of the water conservancy hub is a control project in the inland waterway regulation project.Taking the prototype observation practice of the second line ship lock project of the Youjiang Jinjitan hydro-junction as an example,this paper analyzes and summarizes the methods of prototype observation for ship lock renovation and expansion,mainly including five observation methods,such as gradient observation,surface velocity direction measurement,cross-sectional flow and flow velocity direction observation,sediment testing,and sediment sampling.Through on-site practical production,multi-dimensional synchronize observation and sampling are carried out in the upstream and downstream of the hub,and the observation results are statistically analyzed and studied to provide hydrological basic data for the planning,design,and construction technical schemes for the hub ship lock expansion and renovation,providing accurate engineering implementation data for model testing and waterway regulation project.It is worth learning and applying in similar projects.