In order to improve the operation reliability of single-stage ship lock，we carry out the reliability analysis of a single-stage ship lock system. Through the function structural analysis of the system and equipment，we draw the corresponding reliability block diagram，establish the operation reliability model，obtain the reliability of the single-stage ship lock system and equipment according to the failure statistics of each equipment in recent years，and propose the corresponding measure for the weak link of the system. The results show that the reliability of the miter gate and hoist of single-stage ship lock is the highest，and the reliability of the electrical control system is the lowest. The sensor and water stops are the weak links of the system. The system stability can be significantly improved by using redundant configuration，technology innovation，rapid maintenance，and other technologies.