Aiming at the deposition of foreign body in a lock chamber during the operation of ship lock，the influence of foreign body in a lock chamber on the operation and navigation efficiency of miter gate equipment is analyzed. The development of the stop-water anti-blocking device came up with an innovative structure type that could prevent foreign bodies from falling to block the miter gate. It is proved that the device can effectively protect the operation safety of the miter and improve navigation efficiency after the installation in the Three Gorges Ship Lock. The result has a great value of popularization and application，which promote the development of design and manufacturing technology of miter gate.