为解决钢绞线锚下有效张拉力缺乏可靠随机抽检方法的问题，从力学平衡和变形协调条件出发，推导了反张法检测单根钢绞线锚下张拉力的力学机理，分析了其最不利条件下的理论测试误差，指出了该方法的适用条件。最后结合常用施工机具和设备，提出了一种非常实用的测试方法和系统组成，并在室内静载锚固试验机上进行了验证。试验结果表明: 采用该方法测试钢绞线锚下张拉力时，夹片与锚具拉脱临界时刻前后不同参数曲线的敏感性依次是: 力 － 位移曲线 ＞ 力时程曲线 ＞ 位移时程曲线，该方法的测试精度能够满足工程精度要求。

In view of the lack of reliable testing methods for the effective tension of end anchor of external prestressed strand，the mechanical mechanism of testing the tension of end anchor by the reverse tension method was revealed based on the mechanical mechanism of mechanical equilibrium and deformation coordination． And the theoretical testing error under the most unfavorable conditions was analyzed，and the applicable conditions of the method were pointed out. Finally，based on the most commonly used construction machines and equipment in the construction site，a practical test method and system composition were put forward and verified on the indoor static load anchorage test machine． The test results show that the sensitivity of different parameter curves in judging tension force under strand anchor is:  forcedisplacement  curve ＞ force-time curve ＞ displacement-time curve． The test accuracy of the proposed method can meet the requirements of engineering accuracy．