The invention discloses an approximately horizontal high-pressure-bearing drill hole sealing device, which comprises a grouting pipe, a fracturing pipe and a slurry return pipe, wherein the outside of a hole opening of a high-pressure-bearing drill hole is provided with an expansion hole; an inner step formed between the expansion hole and the high-pressure-bearing drill hole is provided with a part positioned above an upper busbar of the high-pressure-bearing drill hole; a plurality of grouting holes are formed in the inner end of the grouting pipe in a floral pipe shape; a plurality of water outlet holes are formed in a pipe section, positioned at the inner end of the high-pressure-bearing drill hole, of the fracturing pipe in a floral pipe shape; a flexible pulp blocking section is also arranged on the fracturing pipe, and is positioned between the floral pipe section of the fracturing pipe and the inner end of the grouting pipe; the floral pipe section, provided with a slurry return hole, on the slurry return pipe is positioned in the expansion hole; a pipe opening position of the slurry return pipe is higher than an upper busbar of the expansion hole; and pipe openings of the grouting pipe, the fracturing pipe and the slurry return pipe are exposed outside the expansion hole. The approximately horizontal high-pressure-bearing drill hole sealing device has the beneficial effects that the structure is simple; the hole sealing speed is high; the influence of a contraction joint on the sealing effect can be effectively eliminated through a formed sealing hole; the hole sealing effect is good; and the bearing pressure is high.