Optimized design of cold chain insulated box must be considered to maintain and control the temperature in order to maintain the fresh condition for temperature-sensitive food and medicine at least 72 hrs. In this paper, heat flow of cold chain insulated box with phase change material (PCM) is analysed by the COMSOL Multiphysics with variable thickness of insulation panel, and fabricated and experimented according to the simulated conditions and compared with results. As a result, the method for fabricating an optimal design through simulation for optimizing heat flow characteristics was considered.