The invention provides a data directional transmission system, which is used for directionally transmitting data in a first network segment and a second network segment. The data directional transmission system comprises a database server, a transitional server, a firewall, a web server and an intermediate pool data server, wherein the database server and the transitional server are located in the first network segment, and the web server and the intermediate pool data server are located in the second network segment; when the first network segment and the second network segment belong to different network segments, the second network segment acquires data in the database server via the transitional server, and the acquired data is transmitted based on the TCP protocol and is written into the intermediate pool data server based on a component object model (COM); and when the first network segment and the second network segment belong to the same network segment, the second network segment acquires data directly from the database server. The data directional transmission system provided by the invention can achieve high-efficiency and stable transmission of big data.