This study reports the synthesis and characterization of two Fe(II) spin-crossover (SCO)-based catenated metal-organic frameworks (catena-MOFs), 1Ag and 1Au, which exhibit both thermal- and light-induced spin transitions. These materials are constructed through the self-assembly of a naphthalene diimide-based bis-pyridyl ligand (BPND), [M(CN)₂]⁻ (M = Ag or Au), and Fe²⁺ in a one-step strategy. The resulting catena-MOFs possess a unique three-dimensional (3D) structure formed by the polycatenation of two-dimensional (2D) layers with hxl topology. Both complexes undergo thermal- and light-induced SCO, and significant changes in emission intensity and dielectric constant are observed during spin state switching. This research demonstrates the dual functionality of coupled fluorescence emission and dielectricity in SCO-actuated bistable mechanically interlocked molecules (MIMs). The spin state of Fe²⁺ ions influences the local electrical dipoles, leading to changes in dielectric properties during spin transition. The study also shows that the SCO-luminescence coupling arises from energy transfer due to spectral overlap in the low-spin (LS) state or changes in local electrical dipoles caused by structural deformation. These findings highlight the potential of SCO materials for practical applications in molecular switches and advanced sensing materials. The mechanically interlocked structure enhances the stiffness of SCO materials, improving the coupling effect between luminescence and SCO. The introduction of SCO units provides magnetic, optical, and electrical properties to bistable MIM materials, making them promising for advanced sensing applications.This study reports the synthesis and characterization of two Fe(II) spin-crossover (SCO)-based catenated metal-organic frameworks (catena-MOFs), 1Ag and 1Au, which exhibit both thermal- and light-induced spin transitions. These materials are constructed through the self-assembly of a naphthalene diimide-based bis-pyridyl ligand (BPND), [M(CN)₂]⁻ (M = Ag or Au), and Fe²⁺ in a one-step strategy. The resulting catena-MOFs possess a unique three-dimensional (3D) structure formed by the polycatenation of two-dimensional (2D) layers with hxl topology. Both complexes undergo thermal- and light-induced SCO, and significant changes in emission intensity and dielectric constant are observed during spin state switching. This research demonstrates the dual functionality of coupled fluorescence emission and dielectricity in SCO-actuated bistable mechanically interlocked molecules (MIMs). The spin state of Fe²⁺ ions influences the local electrical dipoles, leading to changes in dielectric properties during spin transition. The study also shows that the SCO-luminescence coupling arises from energy transfer due to spectral overlap in the low-spin (LS) state or changes in local electrical dipoles caused by structural deformation. These findings highlight the potential of SCO materials for practical applications in molecular switches and advanced sensing materials. The mechanically interlocked structure enhances the stiffness of SCO materials, improving the coupling effect between luminescence and SCO. The introduction of SCO units provides magnetic, optical, and electrical properties to bistable MIM materials, making them promising for advanced sensing applications.