The key performance of super-resolution optical disk storage technique is mainly determined by the mask material. In this work, the super resolution pits on the optical disk are dynamically read out with indium thin film as a functional mask layer. Thin films with different thicknesses are deposited by direct current magnetron sputtering method, the thickness changes with time of the In thin films are measured by profilometer and the different surface morphologies are observed by atomic force microscopy. In thin film in the pre-engraved super-resolution optical disk with pit size of 390 nm is created to form the In mask super-resolution optical disk. The readout is tested by the optical disk dynamic tester, and the largest carrier to noise ratio (CNR) of 26 dB is obtained. To explore the internal mechanism of this super-resolution readout ability, the optical constant under different temperatures is studied by variable temperature ellipsometer. The reflectivity and absorption coefficiency are also obtained. The experimental results indicate that the mechanism of the super-resolution readout with In thin film as mask can be explained by the model of aperture-type super-resolution.