Nano-level Sn-Al alloy thin-film electrode materials prepared by magnetic sputtering technology are characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The charge/discharge and the cyclic voltammograms of the film electrodes are tested by the high precision battery testing system. The results indicate that the materials prepared by direct current and radiofrequency methods have a large difference in performance. The films prepared by DC method have small particles and excellent cycling stability. Its initial discharge capacity and efficiency are 1060 mAh/g and 71.7%, respectively, and the specific capacitance is over 700 mAh/g after 30 cycles. But the films prepared by RF method have the bigger particles and inferior cycle performance, and its specific capacitance initially increases but after 5 times cycle it declines.