A method for preparing biodegradable polymeric microparticles bearing a steroid drug, the method comprising the steps of: (a) dissolving a mixture of a steroid drug and a biodegradable polyester-based polymer in an organic solvent to give a solution containing the steroid drug and the biodegradable polyester-based polymer, wherein the mixture is obtained by mixing the steroid drug and the biodegradable polyester-based polymer at a weight ratio of 1:99 to 3:7, and the mixture is dissolved in an amount of 1-25 % w/v in the organic solvent; (b) spraying the solution containing the steroid drug and the biodegradable polyester-based polymer therein to a hydrocarbon solution of C5-10 maintained at a temperature of less than the melting point of the organic solvent to form microparticles; (c) adding the microparticles to an aqueous salt solution to dissolve and eliminate the organic solvent; and (d) desalting the organic solvent-eliminated microparticles, wherein the organic solvent is dimethyl sulfoxide (DMSO), the steroid-based drug in step (a) is at least one selected from the group consisting of deflazacort, desonide, desoximetasone, dexamethasone, diflorasone, diflucortolone, difluprednate, loteprednol etabonate, rimexolone, mazipredone, medrysone, methylprednisolone, meprednisone, mometasone furoate, beclomethasone, betamethasone, budesonide, algestone, alclometasone, amcinonide, enoxolone, corticosterone, cortisone, cortivazol, chloroprednisone, clobetasol, clobetasone, clocortolone, cloprednol, tixocortol, triamcinolone, triamcinolone acetonide, triamcinolone benetonide, triamcinolone hexacetonide, paramethasone, pregnenolone acetate, prednicarbate, prednisolone, prednisolone 25-diethylaminoacetate, prednisolone sodium phosphate, prednisone, prednival, prednylidene, fluazacort, flucloronide, flumethasone, flunisolide, fluocinolone acetonide, fluocinonide, fluocortin butyl, fluocortolone, fluorometholone, fluperolone acetate, fluprednidene acetate, fluprednisolone, flurandrenolide, fluticasone propionate, formocortal, halcinonide, halobetasol propionate, halometasone, halopredone acetate, hydrocortamate, hydrocortisone, and a sex hormone, the hydrocarbon of C5-10 in step (b) is at least one selected from the group consisting of pentane, hexane, heptane, octane, nonane, decane, and petroleum ether, the aqueous salt solution in step (c) is a 5-30 % (w/v) solution of NaCl or CaCl 2 in water, and the biodegradable polyester-based polymer is at least one selected from the group consisting of poly-lactic acid, poly-glycolic acid, poly-D,L-lactide (PDLLA), poly(D,L-lactic-co-glycolic acid) (PLGA), poly-caprolactone, poly(valerolactone), poly(hydroxyl butylate), and poly(hydroxy valerate). (a) dissolving a mixture of a steroid drug and a biodegradable polyester-based polymer in an organic solvent to give a solution containing the steroid drug and the biodegradable polyester-based polymer, wherein the mixture is obtained by mixing the steroid drug and the biodegradable polyester-based polymer at a weight ratio of 1:99 to 3:7, and the mixture is dissolved in an amount of 1-25 % w/v in the organic solvent; (b) spraying the solution containing the steroid drug and the biodegradable polyester-based polymer therein to a hydrocarbon solution of C5-10 maintained at a temperature of less than the melting point of the organic solvent to form microparticles; (c) adding the microparticles to an aqueous salt solution to dissolve and eliminate the organic solvent; and (d) desalting the organic solvent-eliminated microparticles, wherein the organic solvent is dimethyl sulfoxide (DMSO), the steroid-based drug in step (a) is at least one selected from the group consisting of deflazacort, desonide, desoximetasone, dexamethasone, diflorasone, diflucortolone, difluprednate, loteprednol etabonate, rimexolone, mazipredone, medrysone, methylprednisolone, meprednisone, mometasone furoate, beclomethasone, betamethasone, budesonide, algestone, alclometasone, amcinonide, enoxolone, corticosterone, cortisone, cortivazol, chloroprednisone, clobetasol, clobetasone, clocortolone, cloprednol, tixocortol, triamcinolone, triamcinolone acetonide, triamcinolone benetonide, triamcinolone hexacetonide, paramethasone, pregnenolone acetate, prednicarbate, prednisolone, prednisolone 25-diethylaminoacetate, prednisolone sodium phosphate, prednisone, prednival, prednylidene, fluazacort, flucloronide, flumethasone, flunisolide, fluocinolone acetonide, fluocinonide, fluocortin butyl, fluocortolone, fluorometholone, fluperolone acetate, fluprednidene acetate, fluprednisolone, flurandrenolide, fluticasone propionate, formocortal, halcinonide, halobetasol propionate, halometasone, halopredone acetate, hydrocortamate, hydrocortisone, and a sex hormone, the hydrocarbon of C5-10 in step (b) is at least one selected from the group consisting of pentane, hexane, heptane, octane, nonane, decane, and petroleum ether, the aqueous salt solution in step (c) is a 5-30 % (w/v) solution of NaCl or CaCl 2 in water, and the biodegradable polyester-based polymer is at least one selected from the group consisting of poly-lactic acid, poly-glycolic acid, poly-D,L-lactide (PDLLA), poly(D,L-lactic-co-glycolic acid) (PLGA), poly-caprolactone, poly(valerolactone), poly(hydroxyl butylate), and poly(hydroxy valerate).