The invention discloses a treating method for a pre-prepad fluid used for fracturing. The method comprises the following steps: (1) determination of a basic formula for the pre-prepad fluid; (2) optimization of a comprehensive formula for the pre-prepad fluid by increasing the concentration of an anti-swelling agent in the case of high water sensitivity, increasing the concentration of a thickening agent in the case of high acid sensitivity, changing the concentration of a pH value regulating agent in the case of high alkali sensitivity, adjusting the concentration of a cation-containing additive in the case of high salt sensitivity, controlling output after fracturing in the case of high velocity sensitivity, or adding an acid solution additive in the case of high stress sensitivity; (3)optimization of the displacement and liquid volume of the pre-prepad fluid: carrying out construction under the condition of high displacement of 1.5 to 2 m<3>/min to fracture a seam with a height 80%of an expected seam height and then carrying out construction at low displacement of 0.5 to 1 m<3>/min; and (4) optimization of a ratio of the viscosity of the pre-prepad fluid to the viscosity of aprepad fluid, wherein the viscosity of the pre-prepad fluid is allowed to be smaller than the viscosity of the prepad fluid. Directed at fracturing demands of different reservoir strata, the method optimizes the formula, usage amount, displacement, viscosity and the like of the pre-prepad fluid, so the yield increasing effect of the reservoir strata is maximized.