锦屏—苏南±800 kV特高压直流线路采用了液压式接续金具和耐张线夹，金具的握力应不小于95% RTS。900 mm2大截面钢芯铝绞线是4层铝股结构，而且JL/G3A-900/40导线铝钢比较大。研究了金具对大截面导线握力的影响因素，结果表明压接造成的单线强度损失是客观存在的，导线的铝钢比、单线强度是影响金具握力的主要因素。

Jinping-Sunan ±800 kV UHV DC line uses hydraulic splicing fitting and strain clamp, and the grip strength of fitting should be more than 95 % RTS. Because 900 mm2 large cross-sections ACSR was 4-layer aluminum stranded structure, especially the aluminum/steel ratio of JL/G3A－900/40 conductor was larger, this paper mainly studied the influence factors of fitting on the grip strength of large cross-section conductor. The result shows that there is a wire strength loss caused by crimping, which is the main influence factor, as well as aluminum /steel ratio.