The concept of the interference-free underground heat exchange well is to pre-heat the circulating medium with the natural ground heat in mid-deep to deep wells and provide auxiliary heating in winter, achieving energy conservation. It is a closed loop system with the sealed metal heat exchanger and a kind of green heating method, since it recovers only heat without consuming water. With the features of environmental protection, cleanliness and low carbon without pollution, it will be one of the most important means for clean heating in north China. This paper presents the heat exchange system and the completion technology.