Employing computer techniques to visualize the aging of Dunhuang Frescoes is of great significance since the audience can re-experience this process. But previously, because colorimetric and chemical modeling was not introduced to the Dunhuang Mural aging simulation system, there was a lack of objectivity. In this paper, however, the color-changing model is based on colorimetric and chemical modeling. Since this modeling describes the natural behavior of the color changing process, the simulation result is quite impressive. In this article, first, the former related works is reviewed. Then, three modeling methods are narrated. After that, the simulation result is shown and discussed. And finally, future research is suggested.