High-water-pressure small-dip-angle horizontal drilling coring device and using method thereof

The invention relates to the technical field of drilling construction, in particular to a high-water-pressure small-dip-angle horizontal drilling coring device and a using method thereof. Comprising a thick shield shell steel plate, a drilling assembly, a guide assembly and a sealing assembly. One end of the guide assembly is connected with the outer portion of the thick shield shell steel plate, and the other end of the guide assembly is provided with a plane used for drilling of the drilling assembly. The sealing assembly is connected with the end, provided with the drilling plane, of the guide assembly. The drilling assembly is arranged in the sealing assembly in a sleeved mode, and drilling and coring are conducted on the thick shield shell steel plate along the end, provided with the drilling plane, of the guiding assembly. The device not only can simultaneously push an upper drill rod and a lower drill rod in opposite directions to enable the drill rods to be quickly centered, but also is simple in stru