Abstract: Generally, the higher the gas content of the coal seam is, the greater the development potential of the corresponding coalbed methane well. However, due to the influence of geological, engineering and mining factors, the high gas coalbed methane wells also have low or no gas production, resulting in serious losses in the development of coalbed gas. Through the analysis of the geological, fracturing and drainage characteristics of abnormal wells （high gas content and no gas production） in Malan well field, the mechanism of abnormal wells and the corresponding reconstruction measures are obtained. Abnormal wells have the characteristics of high gas content and no gas production, abnormal fracturing curve, abnormal high water production and hydrochemical abnormality, and there is a causal relationship between each abnormal feature. The direct cause of high gas content but no gas production in abnormal wells is long-term high yield water, and the fundamental reason is the connection between No.2 coal seam and aquifer during drilling. In view of the causes of abnormal wells, it is suggested that only No.8 coal seam can be mined by plugging the perforation at No.2 coal seam.