Aryl hydrocarbon receptor (AhR) is known to bind several exogenous ligands such as natural plant flavonoids, synthetic polycyclic aromatic hydrocarbons, and dioxin-like compounds, but its association with KPS-21 is unknown. Therefore, in this study, AhR was explored as an AD-regulating target of KPS-21 for AD regulation using in silico prediction, and pharmacological prediction and various AD-induced models confirmed that KPS-21 exhibited pharmacological activity through AhR regulation. In this study, AhR was explored as an AD-regulating target of KPS-21 for AD regulation using in silico prediction, and pharmacological prediction and various AD-induced models confirmed that KPS-21 exhibited pharmacological activity through AhR regulation. The results of the study showed that KPS-21 regulated epidermal differentiation terminal proteins through the AhR pathway in HaCaT cells stimulated with TNF-α/IFN-γ, and this phenomenon was the same in AD-induced mouse models and RHS models. In this study, AhR was explored as a KPS-21-AD combined treatment target through in silico prediction analysis, and KPS-21 was proven to have an AD treatment effect through AhR regulation in vitro & vivo and in the RHS model. In particular, KPS-21 can be used as a potent inducer of AhR signaling because it protects against AD by enhancing epidermal terminal differentiation through the AhR-mediated pathway in keratinocytes.