Abstract:IEC61850 communication has been widely used in electric power system,and SCD file is adopted to describe the Substation Communication System.Hierarchical structure of the SCD file is an XML format,making it not suitable for direct text comparison methods.Meanwhile,the levels of SCD file hierarchy are too many for pure structured comparison methods,which make them lack of time and space efficiency.Based on characteristics of the SCD file,this paper proposes a hierarchical combined approach of structured match and text comparison.Firstly,we abstract critical attribute names with hierarchy information of IED/AccessPoint/LDevice and compare the hierarchy correspondently with structured comparison method which is based on critical attributes.Secondly,we compare the content of LNode with what is based on longest common subsequence algorithm.This combined method could remove invalid differences arising by sequence modification,and could complete the comparison much faster with more accurate and straight forward comparison results.