During daily operation of Substation, if Gas Insulated Switchgear (GIS)equipment breaks down, it will lead to the suspension of substation power supply, and national production and life cannot be guaranteed. This paper discusses how to locate the breakdown of GIS efficiently and effectively. The Distributed Acoustic Sensing (DAS) system described in this paper is combined with Support Vector Machines (SVM) in machine learning method, which can realize fault location and facilitate fault elimination. At the same time, it is of great significance to restore the power supply of substation in time.