ANSYS program is applied to the numerical analysis on the space flexibility and elastoplasticity of a spiral(V-notch),which suggests that: 1)The stress distribution is uneven inside the spiral V-notch as tensile stress is focused near the tip of the notch.2)Tensile stress and compressive stress areas are located alternatively inside the whole notch,the stress changes slower at a point farther from a crack tip,and much faster at a nearer point.3)Elastoplasticity study finds that there exists at the tip of the crack a plastic zone that expand and extend to the direction of the tip with increase load so that cracks initiate at the tip of the notch and extend in the direction of the tip.