Abstract: Big data, which is today’s hottest technical vocabulary, is setting off a global thinking change, and become the forefront of a new round of technological and industrial competition. Big data technology has an immeasurable role to enhance the core competitiveness of China Railway and promote the transformation and upgrading of the railway. This paper expounded the basic concept and characteristics of railway big data, analyzed the current situation and demand of railway big data application, designed the overall architecture of railway big data platform, analyzed the key technologies, provided some guidances to promote the implementation and application of big data technology in China Railway.