<p>Multilayer structures composed of quasi-zero-stiffness (QZS) units exhibit mechanical characteristics distinct from those of a single unit, and their behaviors are governed by the coupling mechanism between the QZS units. This paper introduces the coupling coefficient to quantitatively describe this mechanism, classifying the system into strongly coupled and weakly coupled states. Through theoretical analysis, numerical simulation, and experimental testing, the static and dynamic responses under different coupling states are comparatively investigated. The results show that in the strongly coupled system, the deformation behavior of each QZS unit shows high consistency, leading to a wider QZS region, weaker nonlinear characteristics, and stronger dynamic response. In the weakly coupled systems, the low degree of deformation coordinations among the units results in different QZS regions, enabling low-frequency vibration isolation under varying loads. The analytical approach of the coupling mechanisms and the static and dynamic response behaviors generated by the two coupling mechanisms provide guidance for the structural design of multifunctional and highly adaptable multi-level QZS metamaterials.</p>