The great and fast variation of water level has always been the focus of operation management of the Three Gorges ship lift.To ensure safety,strict control conditions are adopted in the trough docking position in the design,but it also frequently causes the fault of stop position and increase of reposition,which seriously affects efficiency.In view of the low efficiency of accurate stopping,we study the docking stopping mechanism,optimize the control value of the deviation between the trough location and the channel water level and add measures of manual intervention based on the automatic control mode of following water to calibration target position to improve the exact stopping condition and docking efficiency. Analyzing the variation law of the channel’s water level and characteristics of the trough displacement and the driving motor speed during the docking stopping,we obtain the difference between the downstream and upstream,present the idea to degrade the slope of speed control curve to improve smoothness. It provides reference for the improvement of the safety and efficiency of the ship lift operation.