作为衡量电接触性能的重要参数，接触电阻的大小直接关系到电气设备的运行状况。目前主要采用离线的实验测量手段对接触电阻进行测量，测量结果与实际运行状态存在一定的差异; 文中提出了一种基于轴向热路模型的接触端面接触电阻的计算方法。首先，以架空地线与预绞丝接触端口为研究对象构建轴向热路模型，其中模型的热参数采用遗传算法获得; 然后结合 GJ-50 架空地线的实例计算结果，讨论分析了模型热参数和接触电阻的变化规律。研究结果表明: 利用文中所提出的方法，可以准确得到接触端面暂态温升过程中不同温度对应的交流接触电阻，并且稳态温度下接触电阻随着加载电流的增加而减小，但不受时间计算步长的影响; 该计算方法的准确性很高，接触电阻的实验测量结果和计算结果最大误差不超过 9%; 接触电阻与温度的关系采用 Paulke 等提出的公式表示时计算结果更为准确。

As an important parameter for the electrical contact performance measurement，the size of contact re-sistance is directly related to the operation of electrical equipment． At present，the contact resistance is usually measured with the off-line experimental measurement method，but the measurement result often differs from the ac-tual operating state to a certain extent． So a method for calculation the contact resistance of contact surface based on the axial thermal circuit model was proposed． Firstly，an axial thermal circuit model was constructed taking the contact terminal of overhead ground wire and armor rod as the research object，and the thermal parameters of the model were obtained by genetic algorithm． Then，based on the calculation results of the GJ-50 overhead ground wire，the variation laws of thermal parameters of the model and contact resistance were discussed and analyzed．The results show that the AC contact resistance corresponding to different temperature during the transient tempera-ture rise of contact surface could be obtained accurately by using the proposed method． The contact resistance de-creases with the increase of load current under the steady state temperature，but it is not affected by the time calcu-lation step． The calculation method shows a high accuracy，and the maximum error between the experimental measurement results and the calculation results of contact resistance does not exceed 9%． In addition，the calcula-tion result is more accurate when the relationship between contact resistance and temperature is expressed by the formula proposed by Paulke et al．