Abstract: The principle of Formal Language and Auto Machine is build up to translate nature language into languages which can be identified and processed by computers.Text information can be intelligently monitored using finity auto machine.Information that is necessary for system monitoring can be obtained through the syntax analysis of text,it gives us a particular statement of the using of finity auto machine in the bulletin board system information monitor,and makes a general analysis of three types of Information monitor,Terminal monitor, Running monitor and Backup monitor. and also gives us a material solution of them,and gives us a vivid description of designing the system and software interface.