At present,the design specification does not clearly define the basis for selecting the Z-value of the front and rear water pressure difference in the formula for calculating the opening and closing force of the miter gate.The designer selects a large value when calculating the opening and closing force of the miter gate,so it leads to engineering waste.We carry out the numerical simulation and physical model test of the hydrodynamics and opening and closing characteristics of the miter gate of Datengxia ship lock,and analyze the effect of the factors affecting the opening and closing force quantitatively in order to select the Z-value more scientifically and reasonably.The results show that increasing the clearance of the door bottom,the depth of the sill and the use of the variable speed opening and closing mode are beneficial to the smooth flow of water before and after the gate.The Z-value during the opening and closing process is small,and the corresponding opening and closing force of the herringbone door is also small.Considering the main influencing factors of hydrodynamic characteristics of the opening and closing of the miter gate,the Z-value can be reasonably selected to obtain more accurate calculation results and optimize the capacity of the hoist.