大量程引伸计的弹性元件处于大挠度工作状态，引伸计非线性问题较为突出．本文设计出双折臂结构的弹性元件，理论上可使非线性误差获得完全自补偿，在较大量程内测端挠度与弹性元件上应变呈线性关系，较圆满地解决了大量程引伸计设计中的非线性问题，显示出该结构形式独特的优点，实验结果令人满意 A large number of extensometer elastic element in the work of large deflection, extensometer nonlinear problem is more prominent. In this paper, the elastic element with double-folded arm structure is designed. In theory, the nonlinear error can be completely self-compensated. In a larger range, the deflection at the measuring end has a linear relationship with the strain on the elastic element, which satisfactorily solves the problem of large-scale extensometer design In the nonlinear problem, showing the unique advantages of the structure, the experimental results are satisfactory