某220kV输电导线发生断线事故，通过宏观观察、对边距尺寸测量、断口分析、拉断力试验、化学成分分析等方法对导线断裂原因进行了分析，并研究了压接工艺参数对导线拉断力的影响。结果表明：钢锚环箍未被压接或压接数不足会明显降低导线的拉断力并改变导线的受力状况，使钢锚出口处强度相对较低的钢芯成为受力最大部位，而后钢芯受力断裂导致输电导线断裂。

A fracture accident occurred on a 220 kV transmission wire. The reasons of fracture were analyzed by macroscopical observation, margin size measurement, fracture analysis, breaking force test, chemical composition analysis and so on, and the influence of crimping process parameters on transmission wire breaking force was also studied. The results show that the steel anchor hoop was not pressed or the number of compression joints was insufficient, the tensile force of the wire will be significantly reduced,and the stress state of the wire will also be changed, which makes the steel core with relatively low strength at the outlet of the steel anchor became the maximum force position. Then the steel core was fractrued by force, led to the fractune of the transmission wire.