Plane valve is the commonly used valve type for ship lock.Under the effect of medium-high head,the valve lintel,root edge and gate slot are easy to produce the cavitation corrosion and the derrick of the valve hoist is easy to be compressed and unstable.Based on the water transmission model test,the problem of cavitation of the lintel,root edge and gate slot has been solved using a natural ventilation method .There are some misaligned holes in the back board of the valve and the “∧” stress flow channel is retained,which can meet the nature ventilation,and at the same time improve the strength and rigidity of the valve so as to avoid the formation of pontoon and ensure the installation of the main roller and side sealing.Nylon blocks are set behind the top sealing to extend the time that the top sealing separating from the lintel,which can prevent the top water flow from being interfered with the bottom water flow prematurely and reduce the pressure fluctuation and sound vibration.Through the upstream face setting of the bottom sealing，the uplift force in valve closure is reduced,and the derrick of the valve hoist is always in tension without setting the counterweight;which avoids the instability of derrick under pressure and achieves the normal operation of the valve with smaller opening and closing force.