The closing process of high-head plain gates was numerically simulated with the RNG k-ε model, VOF method, and dynamic mesh division technique. The reliability of the numerical method was verified with measured data. The trend term of bottom edge pressure was extracted using empirical mode decomposition(EMD), a processing technology of a nonstationary random process. The relationships between the bottom edge type, flow fluctuation, and holding force were examined. The optimal bottom edge type was determined through comprehensive consideration of the pressure fluctuation, cavitation, and holding force characteristics of the bottom edge. The results show that the type of bottom edges of gates has a significant influence on the opening and closing forces, and a bottom edge with a front inclination leads to the minimum opening and closing forces, lower pressure fluctuation, and less cavitation damage.