Abstract: In order to achieve lithographic pattern with sub-diffraction resolution, a phase-change lithography system was designed. By using a pulse delay technology, digital signal with resolution of 1ns and adjustable pulse width was generated to drive the laser and obtain laser pulse with the corresponding width. With the aid of LabVIEW software and single chip microcomputer, communication between parts of system and computer and all system auto-lithography processing were obtained. By using Ge2Sb2Te5 thin film as base material and its optical properties, an innovative and fast autofocusing method to phase-change material was proposed. In the experiment, Ge2Sb2Te5 crystallization pattern with line width of 0.69m was obtained by phase-change lithographic system. The dimension of crystallization pattern is less than laser focus spot. The results show that the system has the advantages of high-precision, easy operation and low cost. The study has significance for simple phase-change lithography systems.