Compared to concrete and steel structures, research on the blast resistance of timber structures is relatively scarce. Although there have been experimental studies on the blast performance of light-frame wood walls, relevant numerical studies remain limited. This paper addresses the numerical modeling of light-frame wood walls under blast loads, with a focus on the determination of the dynamic increasing factor (DIF) for nail connections and the failure criteria for wood studs. Based on the partial composite theory, this study provides a reasonable value for the DIF of nail connections by introducing experimentally measured DIFs for wood studs and wood-frame walls. On this basis, a finite element (FE) model for blast resistance analysis of light-frame wood walls is developed. This model considers the orthotropic characteristics of wood-based structural panels, the nonlinear dynamic behavior of nail connections, and the dynamic elastic-plastic features of wood studs. Verification of the developed model against the experimental data indicates that it can accurately predict the dynamic response of light-frame wood walls under blast loads, as well as the time and corresponding peak displacement when wood studs fracture. FE analyses also show that if the variation of the studs’ material properties is reasonably accounted for, the predictions of the dynamic response and failure mode after the fracture of studs are also in good agreement with the experimental results. The developed model paves the way for assessing the blast vulnerability of light-frame wood structures in future research.