在简要介绍裂纹技术及断裂设计概念的基础上，讨论了应力法断料的概念及特点，确定了适宜于低应力脆断的敏感应力状态和最佳预荷方式，以表征切口尖端附近应力场强的无量纲因子ｆａ（ａ／ｂ）为基础，通过实验和数值计算得出包括切口尖端半径、切口深度和切口张角在内的适宜切口参数，从而为应力法下料的应用提供了技术保证。 Based on the brief introduction of the crack technology and the concept of fracture design, the concept and characteristics of the fracture method of the stress method are discussed, and the sensitive stress state and the optimal preloading mode suitable for the low stress brittle fracture are determined, in order to characterize the stress field near the notch tip Based on the strong dimensionless factor fa (a / b), suitable notch parameters including notch tip radius, notch depth and notch angle were obtained experimentally and numerically, which provided the technique for the application of stress cutting Guarantee.