As the core subsystem of the ship lift, the drive system of the Three Gorges ship lift provides power for the operation of the ship lift, and its failure will directly affect the stable and safe operation of the ship lift. In view of the shortcomings of the existing evaluation methods for the failure hazard of the Three Gorges ship lift drive system, such as strong subjectivity and unreasonable weight of evaluation indexes, a failure hazard evaluation method for the Three Gorges ship lift drive system was proposed based on combined weighting and TOPSIS method. The effectiveness and feasibility of this method are verified by simulation of the Three Gorges ship lift drive system, which provides a new evaluation method for failure hazard analysis of key components of the Three Gorges ship lift.