Thin wire simulation is a typical multiscale problem in time-domain computational electromagnetic methods. This article addresses the shielding effectiveness of thin wire cages, and such models can be attributed to complex thin wire structures with multiwire junctions. The discontinuous Galerkin time-domain method for Maxwell's equations is used in our study, and the one-dimensional finite-difference time-domain method is used to construct the iterative scheme for the thin wire. The thin wire is expressed by the modified telegrapher's equations proposed by Holland. In this article, the mesh size is determined by the wavelength of the electromagnetic wave to be analyzed without considering the radius of the thin wire. There is no physical presence of thin wires in our model, and thin wires are expressed by current elements. The proposed method supports the simulation of arbitrarily oriented thin wires, and the proposed method can easily handle complex wire structures. The calculation efficiency can be greatly improved after avoiding multiscale modeling.