介绍了由法国Ｂｅｒｅｍｉｎ提出的局部法理论基础和基本参量─威布尔指数ｍ和临界解理应力σｕ的确定方法。并结合海洋平台用钢Ａ５３７采用ＬＢ５２ＮＳ施焊的接头焊缝金属进行了局部法的探讨。给出了在低温下缺口半径分别为１．２５，２．５０和６．４０ｍｍ拉伸试件的断裂载荷及通过有限元程序计算所得的威布尔应力σω，最后通过统计分析确定出经验与理论分布拟合良好的ｍ值和σｕ值，可用于焊接结构的防断设计和安全评定。 The basic theory of local law proposed by Beremin in France and the method of determining the critical stress σu of Weibull index m are introduced. Combined with offshore platform steel A537 using LB52NS welded joints weld metal were discussed in the local law. The fracture loads of tensile specimen with notch radius of 1.25, 2.50 and 6.40 mm respectively at low temperature and Weibull stress σω calculated by finite element program are given. Finally, the empirical and theoretical analysis Distribution of good fitting m value and σu value, can be used for the anti-fracture design of welded structures and safety assessment.