利用下行通风开采因客观条件限制，正常通风下不能满足安全需要的煤层，既经济又简捷，是急倾斜煤层下行通风开采的成功尝试。 Utilizing the downward ventilation to mine the coal seam which can not meet the safety requirement due to objective conditions and under normal ventilation, it is not only economical but also simple, and it is a successful attempt of downward ventilation mining in steep seam.