Abstract: In order for firefighters to accurately understand the fire situation, we design a smart helmet system based on kalman filter which has integrated the microcontroller system, gas sensors, temperature sensors, wireless communication module, anomaly wearing detection module and alarm module, and the system design consists of the design of software system and hardware system. The hardware system takes the STM32 microprocessor as the core, and wireless GPS module is adopted together with inertial navigation module for the purpose of higher positioning owing to their compensation effects. And it also includes an environmental information acquisition sensor. On the software, the Kalman filtering algorithm is applied to process the collected data, which reduces the influence of sensor delay and noise on the system measurement, so as to achieve accurate prediction of the system state，and the monitoring system software was verified. At the same time, the attitude detection algorithm realizes the accuracy of the firefighter state identify. This paper also conducts an ergonomic analysis of the intelligent fire helmet, and integrates the various components on the helmet. After testing, the system runs stably and has high accuracy.

Key words: fire helmet, Kalman filter, localization technology, ergonomics