Abstract: In order to promote the research and popularization of the seismic mechanical properties of modular prefabricated structure buildings, this paper constructs a mechanical model of key nodes of unbonded modular prefabricated frame structures, and the characteristics of displacement amplitude variation under different vibration conditions were analyzed. Experimental models of assembly frame structures and ordinary frame structures were designed, and unidirectional fixed-frequency sinusoidal vibration load tests were conducted. Factors representing the displacement response to fixed-frequency sinusoidal vibration for both structures were formulated, and comparative analyses were performed from multiple perspectives, including structural displacement, horizontal acceleration response of each floor, and vibration response of shear stress between modules, to assess the seismic stability of assembly frame structures relative to ordinary frame structures. The research findings indicate a high degree of consistency between the theoretical and experimental displacement values of assembly structures, affirming the rationality of modular assembly structure design. Compared to ordinary frame structures, non-adhesive modular assembly frame structures exhibit smaller displacements under high-frequency vibration conditions and tend to have more stable horizontal acceleration dynamic characteristics. Monitoring results of shear stress between modules in assembly structures reveal that the variation in shear stress at column nodes is more significant than at edge column nodes, highlighting their critical role in resisting shear forces and influencing the stability of assembly structures.