Aiming at the problem that the upstream approach channel of Yanzhou Hub Ship Lock renovation project cannot be arranged as a straight and fully sheltered approach channel due to flood discharge,ecological protection,and river regime constraints,physical model tests are used to study the navigable flow conditions of the upstream zigzag non-sheltered approach channel.A 1:100 scale physical model is developed to analyze the navigable flow conditions in the approach channel.The conclusions indicate that:1) Although the fully sheltered long guide wall scheme meets the navigable flow condition requirements,the flow velocity at the 15 m gap reaches 5.23 m/s,causing serious local scouring.2)Without lowering the navigation standards for ships entering and leaving the lock,a proposal combining hydrological statistical analysis suggests setting separate berthing sections for the medium-dry season and the flood season.During the medium-dry season (Q≤2,500 m3/s),the maximum flow velocity in the berthing section is 0.50 m/s,which meets the code requirements.During the flood season (Q ＞2,500 m3/s),the maximum transverse velocity in the entrance area is 0.44 m/s,the maximum longitudinal velocity is 1.23 m/s,the maximum transverse velocity in the connecting section is 0.21 m/s,and the maximum longitudinal velocity is 1.79 m/s,all of which satisfy the code requirements.Furthermore,by the use of the upstream anchorage for vessel waiting area,and comprehensively considering the number of affected days and information-based scheduling methods,the impact on ship navigation capacity is limited.The research results can provide a reference for similar non-sheltered ship lock approach channels.