Abstract: In railway marshalling station integrated automation system, the data is the basis to ensure the smooth and effective operation of the system, and the data security is the guarantee for the system intelligent. In order to explore the security of system data, the system data security protection system was analyzed from the aspects of data acquisition, transmission, storage and application. This article studied on the protection system which was combined with the environmental protection technology, boundary security technology, communication security technology, access control technology and so on, and put forward suggestions for improving the data security of the system.