Large-diameter self-guiding horizontal drilling machine

The invention discloses a large-diameter self-guiding horizontal drilling machine, and relates to large-diameter horizontal drilling equipment similar to soft rock ore beds for coal mine gas extraction, coal seam water injection and the like. The technical problem to be solved is to provide a self-guiding horizontal drilling machine capable of drilling a large-diameter horizontal deep hole. According to the technical scheme, a chassis system comprises a walking system and a supporting system; a propelling device can do reciprocating motion along the drilling direction; an outer drill rod system comprises an outer drill rod and an outer drill rod driving device for driving the outer drill rod to rotate; an inner drill rod system comprises an inner drill rod and an inner drill rod driving device for driving the inner drill rod to rotate, and further comprises two inner drill rod oil cylinders for pushing the inner drill rod driving device to reciprocate in the drilling direction; the inner drill rod is sleeved