The invention discloses a method for preparing powdered oil by compounding octenylsuccinic anhydride (OSA) modified starch with xanthan gum, and belongs to the field of micro-encapsulated powdered oilpreparation. By selecting a mixture of the OSA modified starch and the xanthan gum as a wall material, the method for preparing the powdered oil by compounding the OSA modified starch with the xanthan gum is capable of solving the technical problems of low encapsulation efficiency, poor stability and the like of the micro-encapsulated powdered oil. The method for preparing the powdered oil by compounding the OSA modified starch with the xanthan gum comprises the following steps: step one, dispersing corn starch in an HCl solution of which the concentration is 0.65M, carrying out reaction in water bath at 50 DEG C for 0-24 hours so as to obtain a mixed solution, adjusting pH value of the mixed solution to neutral, terminating acid hydrolysis reaction, and carrying out centrifuging-drying so as to obtain hydrolyzed starch; step two, dispersing the hydrolyzed starch in an aqueous solution so as to obtain starch slurry, adding an OSA solution into the starch slurry within 2 hours with thepH value of the starch slurry kept at 8.5, continuing reaction for 1 hour, adjusting the pH value of the starch slurry to 6.5, Performing centrifugal water-washing on the starch slurry, and carryingout drying so as to obtain OSA modified starch; step three, mixing the OSA modified starch with the xanthan gum at room temperature for 24 hours so as to obtain wall material suspension liquid; step four, adding soybean oil into the wall material suspension liquid obtained in the step three, carrying out homogenization, and carrying out high-pressure homogenization for 2 times; and step five, carrying out spray-drying so as to obtain the powdered oil. The method for preparing the powdered oil by compounding the OSA modified starch with the xanthan gum is novel and rational in design, as well as simple in process; and moreover, the method also has the characteristics of being capable of significantly improving encapsulation rate of the powdered oil, enhancing product stability and so on.