高精度试验机绘出的材料拉伸试验曲线，往往没有明显的初始直线段，用Ｅ－平行线法求得的σ１．２常常具有较大误差。为了降低误差，采用拉伸曲线上０．１Ｆｂ和０．５Ｆｂ两点连线作基准，再以平行线法求σ０．２，这样得到的σ０．２非常接近用“逐步逼近法”［１］得到的σ０．２这种简易方法不仅适合手工图解，而且适合新式试验机，如岛津ＡＧ—Ｅ的计算机图解。 Tensile test curves drawn by high-precision testing machine often do not have obvious initial straight line segments. The σ1.2 obtained by E-parallel line method often has large error. In order to reduce the error, using 0.1Fb and 0.5Fb two points on the tensile curve as the reference, and then using the method of parallel lines to find σ0.2, the σ0.2 obtained in this way is very close to “step-by-step approach” [1] The resulting σ0.2 simple method is not only suitable for manual illustration, but also for the new testing machine, such as computer graphics Shimadzu AG-E.