针对垂度非线性影响下大跨斜拉桥拉索多级张拉控制的问题，根据拉索多级等值张拉和垂度非线性效应基本原理，对多级等值张拉过程进行分阶段计算理论推导，给出施工过程中多种影响因素在理论计算中的修正方法，提出一种新的多级等值张拉计算理论。通过数值分析与实测结果对比，采用该计算理论进行张拉控制的最大误差为-1.25%，最大线型误差为3.3 cm，相较于常规线性方法，该计算理论可大幅提高计算索力均匀性和准确性，且无需进行多次迭代计算，满足实际工程应用需求，可有效指导大跨斜拉桥施工的拉索张拉控制。

In response to the problem of multi-stage tensioning control of long-span cable-stayed bridges under the influence of sag nonlinearity, based on the basic principles of multi-stage equivalent tensioning of cables and sag nonlinearity effects, the multi-stage equivalent tensioning process is theoretically derived, provide correction methods for various influencing factors in theoretical calculations during the construction process, and a new theory for multi-stage equivalent tensioning calculation is proposed. Through numerical analysis and comparison with actual measurement results, the maximum error of tension control using this calculation theory is -1.25%, and the maximum linear error is 3.3 cm. Compared with conventional linear methods, this calculation theory can significantly improve the uniformity and accuracy of cable force calculation, and does not require multiple iterative calculations, meeting the practical engineering application requirements and effectively guiding the cable tension control of long-span cable-stayed bridge construction.