Smart grid is one of the key big data technology applications. How to use big data technology better has a great significance for the establishment of strong smart grid. In this paper, a power big data analysis platform is constructed under the framework of Hadoop/Spark for the smart grid application. Firstly, a company-centric Hadoop and Spark cluster is built. And then combining k-means clustering and integrated decision tree algorithm, a platform framework is given, which can achieve data storage, analysis and prediction. This platform can provide effective theoretical and technical support for typical application fields of power enterprises.