Water level detection for chamber is an important technology for normal operation of ship lock.Based on the current layout of water level gauges in the chamber of Three Gorges ship lock,we take 1#?and 2#chambers of south lock as the test object,add two water level gauges respectively in four wells of two adjacent lock chambers.According to the principle of odd voting method,three water level gauges in each well form an automatic judging mechanism,which can increase the reliability of single point detection of water level,and realize on-line fault detection,abnormal warning and replacement of the fault water level gauge without stopping.It solves the problem that the original single water level gauge cannot realize self-calibration judgment.