As the critical facility of the navigation lock’s function achievement,filling and emptying system design directly influences on the safety and efficiency of lock engineering.Four-section total-balanced filling and emptying system is commonly applicated in high-head large locks domestic and forign.However,the system has the disadvantages of complicated structure and high construction difficulty,also the cavitation problem of its secondary divider.There are the characteristics of inland locks in China,the analysis of domestic and international eningeering data,theoretical and mathematical research,physical model experiment to avoid these disadvantages.The feasibility and applicability of the two-section four-manifold total-balanced filling and emptying system with “long culvert in lock wall + vertical divider at lock center + two-section four-manifold at lock chamber bottom + side ports + open ditches for energy dissipation” has been proved and verified in 40 m-grade single-step giant lock,which provides the reference and basis for high-head large lock designment.