The corn starch was used to determine the optimum technological conditions of corn resistant starch by microwave-enzymatic method. The optimal conditions were got by orthogonal experiment analyses, and we found the content of resistant starch was highest and reached to 28.4%, when treated under the following conditions, i.e. 25% of Starch slurry mass fraction , 800 W of microwave power, 240 s of microwave heating time, and cooling storage for 20 h at 4 ℃. Our study might provide a new clue for the preparation of resistant starch and make benefit for the application for starch industry in the future.