Computer-aided design and simulation software are used in this thesis. AutoCAD is used to create pattern and mask; Pro/E is applied to build 3D model. TracePro software is used to simulate the optical performance. We use software for simulation and analysis. The data from simulation and analysis will be helpful to increase the strike-rate in process. Photolithography process is applied in this thesis for gapless crack polygonal lens array fabrication. In this process, photo resistance, AZ-4620 is spun on the substrate, and expose it after mask alignment, followed by the developing process. The cylinder column with the same size in diameter is formed after this process. Next, apply heat to photo resist. The cylinder structure becomes semi-sphere due to surface tension effect. Then, sputter silver layer on the semi-sphere. The semi-sphere becomes metal mold after nickel electroforming. Nickel alloy core is formed after electroplaing. Then, apply UV cuve resin on the nickel alloy core, and spinning out the extra UV glue. Then, cure it with UV light. Gapless crack polygonal lens array is completed after this series process. The result shows that it can be applied on different optical devices.