Based on the ARM embedded microprocessor and real-time Operation SystemμC/OS-Ⅱ, we develope a fire compound detection system which detects the the gas of CO and CO₂ in the early time when fire happens. Cluster the fire feature with the fuzzy C-means clustering and decide the center of clusters and then report the fire process features based on the fire criterion to the system. The system debuged them successfully. The results of experiments proved that the system can do well in early alarm.It has high identified ability and can decrease the rate of false or missing alarm signedly. Compared to normal system this system can alarm earlier for about 5 minutes.