In recent years, people have improved the ability of data acquisition, storage, analysis and utilization, and big data comes into being. Big data include large capacity structured, semi structured and unstructured data that is difficult to store, analyze and manage in general database software or computer. Characteristics of big Data can be summarized as four Vs, volume, variety, velocity and value. Big data has great potential in the financial sector. Big data finance brings many conveniences to the financial industry, but at the same time, there are some risks and defects. This paper analyzes the risk of big data finance, and puts forward some strategies.