Abstract: Aiming at the existing problems of gas extraction drilling and the drawbacks of wired camera monitoring system in coal mine well, a set of wireless video monitoring system is proposed for the video monitoring of mine gas extraction drilling in this paper based on COFDM technology. The principle and advantages of COFDM technology are introduced; the modulation and demodulation method of COFDM technology are explained; an overall architecture of the video monitoring system and the main parts of hardware design are briefly described in this paper.