Abstract: Based on simulation study of high-pressure gate water seal, we have designed the Three Gorges ship elevator’s gate water seal and have analyzed the seal working performance. In the design process, we selected some relatively optimal seal sections and materials firstly and compared with their working performance about dorsal cavity leakproofness, free overhang of seal head, watertight ability of seal head and gate’s hoisting force by simulation. Finally, we selected optimal seal section and materials. Before then, to design water seal mainly depended on experience and experiment. The design of the Three Gorges ship elevator’s gate water seal has provided a standard design reference based on calculation analysis.