The invention relates to a method for reinforcing a soil body in double-high-pressure stirring and spraying construction, which comprises the following steps of: achieving pile formation through common cutting and mixing based on high-pressure air and cement slurry in the stirring and spraying construction process; and rapidly and uniformly fusing the cement slurry with the soil body by utilizingan inorganic reinforcing agent component to form a reinforced pile body with a better water stopping effect. In the stirring and spraying process, high-pressure air and cement slurry are sprayed out from the bottom of stirring blades respectively, and the high-pressure cement slurry is fused with the soil body to form the stirring and spraying reinforced pile body; the cement slurry is prepared byuniformly mixing main materials and auxiliary materials, adding water and stirring, wherein the water adding amount is 24-28% of the mass of the cement slurry; The main materials comprise, by weight,the following raw materials: 30-50% of sulphoaluminate cement, 15-25% of early strength silicate cement, 25-35% of fine sand, 3-7% of calcium sulfate and 3-7% of calcium carbonate. The auxiliary materials comprise, by weight, the following raw materials: 0.7-1.3% of magnesium oxide, 0.7-1.3% of silicon micropowder, 0.7-1.3% of naphthalene water reducing agent powder and 0.07-0.13% of boric acid.