B Analysis: Big data refers to data sets that cannot be captured, managed and processed by conventional software tools within a certain time range. It is a massive, high-growth and diversified information asset, which needs a new processing mode to have stronger decision-making power, insight and discovery ability and process optimization ability. Big data 4V: large capacity, diversity, low value density and rapidity. Another saying is 5V, including: Reliability: the accuracy and reliability of data, that is, the quality of data. Key technologies of big data: mainly including data collection, data storage, data management, data analysis and mining. However, data analysis and mining is not a unique technology of big data, and it belongs to the category of previous data warehouses. Big data management mainly adopts distributed parallel processing technology.