We theoretically propose a coupled-topological-edge-state waveguide (CTESW), which is composed of stacked binary one-dimensional (1D) photonic crystals with opposite topological properties. The CTESW modes originate from the coupling between a sequence of topological edge states (TESs), which can be verified by the coupled mode theory (CMT). Based on finite element method (FEM), the tunable multiple transmission peaks due to CTESW modes are obtained, and the optical properties of the system can be modulated by the geometric parameters. Besides, the CTESW modes can also be tuned by changing incident angle from 0° to 60° under TE and TM polarization. Moreover, considering the relationship between channel spacing and the frequency spectrum utilization, a dense wavelength division multiplex (DWDM) filter with 50 GHz channel spacing based on CTESW is designed in communication band.