Since 2012, the research of smart grid big data has made initial progress, and relevant researchers and enterprises have made constructive attempts. On the basis of giving the overall framework of big data application in smart grid, this paper lists the application cases of big data technology in distribution network and online monitoring of power equipment. Such as distribution network operation status diagnosis, user behavior analysis, transmission line status assessment, fault diagnosis and prediction technology of transmission and transformation equipment based on complex correlation identification, dynamic evaluation and prediction of key performance of transmission and transformation equipment based on big data and information fusion, etc., the key technologies and research ideas of big data are summarized, and the problems encountered by smart grid big data technology are discussed. Finally, a rational outlook is made for the development of smart grid.

　　The concept of Big Data was first mentioned in th