Valve cavitation is the most important technical issue in the design of a high head ship lock. Domestic and foreign ship lock research and operation experience indicate that under the same buried depth of the valve，the shape of the corridor in the valve section is the main factor affecting the cavitation characteristics of the valve section，resulting in an urgent need to examine the unsteady flow characteristics under different corridor shapes. By investigating an actual project，this paper compares “the corridor shape of top and bottom expansion + the reversed tainter valve” and “the corridor shape of flat bottom and gradual top expansion + the reversed tainter valve” by a model test. A comprehensive comparison of various indicators，such as the hydro-dynamic load characteristics of the corridor in the valve section and the valve opening and closing force characteristics，shows that the former is more suitable for high head ship locks. Nevertheless，this corridor type has its own limitations，such as large engineering amount，complex shape，high construction requirements，and difficult maintenance. In view of various factors，the Qianwei ship lock adopts “the corridor shape of flat bottom and gradual top expansion + the reversed tainter valve” scheme.