Abstract: The accurate dispatching and precise control of the controlling gate of the main channel of the middle route of the South-to-North Water Diversion Project plays an important role in ensuring the safety of the main channel operation，engineering safety and water supply safety.Taking the section from Taocha to Diaohe sluice as the research object，the influence of the quitting operation of Diaohe sluice on water conveyance dispatching and engineering safety was analyzed by hydraulic numerical simulation.The results showed that the water surface line from Taocha to Diaohe sluice decreased 0.18-1.15 m after Diaohe sluice quitting operation.The water diversion capacity of Xiaolou water diversion outlet reduced，but it had little effect on the actual water diversion.The safety factor of anti-sliding and anti-floating stability of canal lining slightly reduced，but it could still meet the safety requirements.The Taocha power plant could prolong the power generation time，increase the power generation capacity and improve the power generation efficiency.The research results can provide reference for the accurate and precise scheduling of the Middle Route Project of South-to-North Water Diversion under the new situation and new requirements.