The invention discloses a method for preparing VI-type slowly-digested starch through ultrasonically-assisted acid-base sedimentation. The method comprises the steps of dispersing common corn starch into a 0.01ml/L KOH solution to prepare a suspension, carrying out ultrasonic treatment at 30 DEG C and 200W for 10min to uniformly disperse the starch to further accelerate to gelatinization and improve the capacity of the starch including fatty acid; gelatinizing the suspension in a boiling water bath for 10 minutes, and cooling to 60 DEG C; dissolving the fatty acid into the 60-DEG C KOH solution, mixing the fatty acid and starch paste, regulating the pH value to 4.7 by using 1.5mol/L tartaric acid, and preserving the heat for a period of time to sufficiently combine the starch and fatty acid; and centrifuging the mixture, washing and settling for 3 times, and carrying out freeze drying to obtain the VI-type slowly-digested starch. A common corn starch-conjugated linoleic acid inclusion complex product is measured to contain 40.62% of slowly-digested starch, and the slowly-digested starch product has a relatively-high nutrient value. X-ray diffraction results show that the slowly-digested starch product prepared by using the method is a VI-type starch complex.