Hydraulic ship lift is a new type navigable building for the high dam，which has no operation experience for reference at home and abroad. To ensure the safe and reliable operation of the hydraulic ship lift and solve the fuzzy problem of risk assessment of important risk sources，we establish the risk factors failure tree of the hydraulic ship lift to identify the operation risk factors and their logical relationship，and propose a risk analysis method based on fuzzy theory for the important risk sources. Taking Jinghong hydraulic ship lift as a research example，we quantitatively analyze the risk level of risk factors，and carry out the risk assessment for the important risk sources of hydraulic system and mechanical system. The results show that this method can objectively evaluate the risk and provide technical reference for risk warning and management of hydraulic ship lift.