A two-step hydrolysis method was evaluated as a potential means of obtaining high yields of furfural and levulinic acid from corn stover using sulfuric acid as catalyst in a water/gamma-valerolactone (GVL) system. The corn stover underwent a high-temperature hydrolysis process to produce levulinic acid, followed by a low-temperature hydrolysis process to produce furfural. A series of experiments were conducted to explore the relationship between the different reaction parameters and the final yields of furfural and levulinic acid. Scanning electron microscopy (SEM) pictures together with X-ray diffraction (XRD) analysis were used to further elaborate on the hydrolysis results. Molar yields of about 70.65% furfural and 57.7% levulinic acid were obtained by applying this method with a low temperature of 140 °C and a high temperature of 190 °C, together with 0.2 M of sulfuric acid used as the catalyst. These results indicated that this was an effective way to obtain satisfactory yields of furfural and levulinic acid from corn stover.