Abstract: The paper focuses on solving the engineering poser of gas emission in the protective seam face exploiting process of Twelfth Mine Ji14-31010 of Pingmei Tian'an Corporation Ltd. With combination of gas and geological condition，for the possible of gas exceeding limit in the mining process of protection layer，the large diameter progressive buried pipe drainage technology is proposed to solve the gas exceeding limit in the mining process. Then the numerical calculation analysis for gas migration in the drainage of goaf is carried out to determine that the reasonable space between buried pipe and drainage pipe diameter is 40 m and 300 mm respectively. Finally，the specific progressive buried pipe with large diameter drainage program is given，which is practiced in the field. Monitoring data in the exploiting process show that the gas drainage by scalar is 29.1~35.3 m3/min，the average gas density is 13.7%，the average gas density in upper corners is 0.51%. And the phenomenon of gas concentration exceeding limits does not appear. This confirms that the puzzle of gas emission in the exploiting process of protective seam face can be rationally solved with the large diameter progressive buried pipe drainage technology.

Key words: Deep mining, Short distance, Low mining height, Progressive, Buried pipe drainage