The invention belongs to the field of information interchange of relay protection devices of a power system, in particular relates to an information interaction method between devices orienting to communication-based regional protection. Required information orienting to communication-based protection function is subjected to modeling and data processing, relay protection sampling value information in larger data transmission volume generates processed stateflow information, so as to reduce information interaction volume between the devices and meet the requirements of communication protection function on network performance; a regional sampling value information acquisition function and an in-region stateflow information interaction function between protection devices in a regional power network are formed by an information communication architecture of an establishment device and a communication architecture of a regional protection system. According to the invention, the contradiction between the information interaction of the relay protection devices and the network transmission performance can be effectively resolved, and a necessary communication function basis is provided for the implementation of a communication-based relay protection system.