通过分析传统输电线路不平衡张力计算方法，得出第1档内应力和计算步长的选取影响计算收敛，传统方法难以保证快速收敛的同时实现高精度计算。提出一种改变步长的不平衡张力计算方法，研究了初值选取方法和步长变换方法，并给出了程序流程。在计算11 种工作情况下，1 个耐张段内的各档应力，传统方法和改变步长方法的计算结果相同，但是改变步长法计算效率大大提高。

Traditional transmission line imbalance tension calculation algorithm is studied and factors which affect traditional algorithm’s convergence are analyzed.A new imbalance tension calculation algorithm with mending steps is studied.And the methods of initial value selected and step mended are studied and the flow chart of the program is presented.Every span’s tension in one section segment under 11 kinds of operating conditions are calculated.The same result is obtained using 2 algorithm.But the efficiency of mending steps algorithm is improved greatly.