This article is based on the engineering background of the research on the equipment characteristics of the fully balanced rack and pinion vertical ship lift structure in the Three Gorges project. It introduces a method of determining the structural bias load and rigid resistance of the steel wire rope by measuring the time varying curves of the motor torque of the upward and downward driving systems of the fully balanced ship lift under different water depth conditions, This method was used to calculate the structural bias load and rigid resistance of the steel wire rope of the Three Gorges ship lift, and to determine the structural bias load caused by a series of modifications to the local structure of the ship compartment and equipment since the trial operation. This provides a basis for further analysis of the performance of the modified Three Gorges ship lift equipment system and corresponding operation and maintenance modifications; At the same time, through the calculation and analysis of the rigid resistance of the steel wire rope, the applicability of the existing design and calculation formula for the rigid resistance of the same direction twisted steel wire rope of the crane to the suspension of large diameter steel wire ropes in the ship lift chamber was verified. The results of this study can provide reference for the design and operation and maintenance management of fully balanced ship lifts.