In the glow wire test, the real-time and accurate monitoring of the flame is the key to the test. In order to reduce the measurement error method of the height and duration of hot wire, this paper presents a new the hot wire measurement system based on a number of digital image processing technology, and combines with the system design principle and MATLAB simulation results to show that this system has high reliability and accuracy, and implement the measurement system using the STM32F407 microcontroller. Finally, using a practical monitoring results of flame burning experiments verifies the effectiveness and accuracy of the measurement system is designed in this paper.