As the single head driving distance increasing in the construction process, large amount of harmful gas because of the blasting and slag-out is difficult to overflow, which influences the construction safety seriously. 施工过程中,随着独头掘进距离的不断增加,爆破及出渣等施工作业过程中产生的大量有害气体不易排出,严重威胁洞内施工安全。