We report the design, analysis, and simulation of the superresolution nanolithography technique based on PDMS soft mold, which obtained the feature size smaller than 1/10 operating wavelength. The proposed nanolithography system consist of a periodic PDMS soft transparent mold, a thin silver layer, photoresist and substrate. The reason why we employ the PDMS soft mold is it can contact perfectly with silver layer. By adjusting the linewidth and the thickness of the silver layer, the optimal contrast were obtained. To analysis the superresolution nanolithography of proposed system, the electric field distributions and electric field intensity are given.