XiaoChaiHuTang is a formula in On Cold Damage with frequent and extensive application. It is greatly appraised. In Qin dynasty, a famous doctor, Qin-Yu Ko, called XiaoChaiHuTang ”the formula of ShaoYang, the king formula to harmonize the exterior and the interior”. The application of XiaoChaiHuTang is still being researched. It is very basic to use XiaoChaiHuTang appropriately in terms of research and apply the theory of On Cold Damage. I would like to share the application of XiaoChaiHuTang in this article.Let's talk about XiaoChaiHuTang in terms of its original quote, mechanism, composition, explanation, related problems, analysis and application.