The forest fires are caused not only inevitably but also accidentally. It is useful to implement dynamically monitoring for forest fire for effectively controlling firing disaster and making use of forest fire. Embedded system has been used widely in remote monitor fields in recent years. The basic monitoring system discussed in this article is composed of ColdFire kernel processor with high-capability and low-consumption, and the open source embedded Linux. By extending RS232 interface and modules, the system builds the fire auto-monitoring platform and provides the system structure and software implementation. The article also discussed the key technologies are given.