Abstract: The construction of a three-level navigation lock at Longtoushan Junction was completed in April 2019. However, it has been found that the design standard was not met, posing a significant safety risk. This study aims to address this issue by analyzing data and conducting physical model tests to understand the navigation flow conditions and identify the underlying reasons. A novel measure was implemented, resulting in a substantial enhancement of the safe discharge. The optimized scheme not only helps meet the design requirements but also provides valuable technical support for engineering design and operation. Furthermore, the newly implemented measures have the potential to be widely adopted and applied in similar scenarios.