This paper presents a deployable-wing multifidelity modeling method based on an asymmetrically gradient-deficient absolute nodal coordinate formulation coupled with unsteady vortex lattice method. Slender deployable wings are composed of multiple bodies connected by hinge joints and can be deployed or folded spanwise during flight. Low-fidelity and high-fidelity deployment simulation models are required for the conceptual and actual design phases of the wings, respectively. The presented multifidelity modeling method can be used for computationally efficient low-fidelity rigid multibody simulation and more realistic high-fidelity flexible multibody simulation. These multi-fidelity simulations are accomplished using a consistent modeling process and the same simulation program architecture. In addition, a consistent methodology can be used to couple an aerodynamic model with the low-fidelity and high-fidelity structural models. To demonstrate the effectiveness of the presented method, we newly present simulations using benchmark slender wing parameters in this paper. To validate the proposed modeling method, wing deployment experiments were performed in a wind tunnel at the Institute of Fluid Science, Tohoku University. Good agreement was found between the simulation using the presented method and the wind tunnel experiments, even when the wings experienced large geometrically nonlinear deformations.