The microwave-assist extraction of pectin from potato starch residue was studied in this paper. The effect of the ratio of liquid to material, pH values, microwave heating time, microwave power and the dosage of aluminum sulfate on the pectin extraction were investigated. The optimized extraction conditions were obtained as follows, the ratio of liquid to material of 15∶1, pH 2, microwave heating time of 5min, microwave power of 04kW, and the dosage of aluminum sulfate of 7mL. The extraction rate of pectin was 18537% under the optimal conditions. The microwave-assist extraction showed many advantages over the traditional method in shortening time, saving solvent and the high yield.