Cross layer drilling separated type whole-course gas extraction hole sealing device and method

The invention discloses a cross layer drilling separated type whole-course gas extraction hole sealing device and method. The device comprises a hole drilled in a coal seam, the top end of the drilledhole is in a drilled hole gas chamber in a second 1 coal seam, the inner cavity of the drilled hole gas chamber is provided with an upper hole sealing pipe, and the lower end of the drilled hole is provided with a lower hole sealing pipe; the wall of the upper hole sealing pipe is provided with a hole sealing pipe fixing device in a sleeve mode, and the upper hole sealing pipe is fed into the upper portion of the drilled hole gas chamber through a pushing rod; an upper bag and a lower bag are arranged inside a cavity formed between the outer wall of the lower hole sealing pipe and the innerwall of the drilled hole gas chamber, and a middle cavity formed by the upper bag and the lower bag is filled with expansion slurry; the lower hole sealing pipe is provided with a slurry injection pipe, and the expansion slurry