Abstract: The paper analyzed echo path of mine-used IP broadcast and talkback system, pointed out that the echo has complex sources, long path delay and large path delay jitter. It proposed a scheme of using software algorithm to eliminate echo in radio host, and using combination of structure design and hardware design to eliminate echo in broadcasting terminal. The practical application shows that the scheme of echo cancellation improves communication quality of mine-used IP broadcast and talkback system, and full-duplex loud-speak and talkback of the system has good effect.