Abstract: In view of the problems of large fire hazards in rural buildings and the difficulty of wiring and false alarms in the existing automatic fire alarm system, a wireless automatic fire alarm system for rural buildings is designed based on Sub-1G and 4G-Cat.1, and the multi-level alarm method of “early warning” and “fire alarm” is adopted to reduce system false alarms. The gateway node used STM32H750 chip as the main control chip, while the sensor node used CC1310 chip as the main control and RF chip. The system design, software control logic and hardware composition scheme were introduced in detail, and the system test was carried out. The results shows that the system can detect smoke and temperature parameters in real time and send pre-alarm and alarm information according to the defined algorithm of the software. The system is of great significance for improving the reliability of real fire detection and ensuring the personal and property safety of residents.