Abstract: Adopting ARM9(S3C2440+Linux) embedded technology,the equidistant system of line heating device is developed,which consists of distance sensors,temperature and humidity sensors,motors,LCD screen,some peripheral hardware and circuit. An electromotor is employed to drive the heater of the line heatind device moving up and down,so keeping the distance of heater and steel plate invariable. The system have the functions of real-time display of temperature and humidity,use key-press setting in Qt to send signals for electromotor to work,phonic alarm and infrared following tract.