To further enhance the maximum applicable height of modular structures in high seismic intensity regions, this study proposes two novel high-rise modular structural systems: the modular structural system with equal-leg angle steel column-to-column connections (ELA-MSS) and the modular structural system based on floor expansion damper connections (FED-MSS). Firstly, the basic configurations and construction procedures of the ELA-MSS and FED-MSS systems were introduced. On this basis, numerical models of the ELA-MSS system with heights of 30 m, 60 m, and 100 m, and the FED-MSS system with a height of 60 m, were developed using ETABS V21.0. The seismic responses of the two systems were investigated in terms of modal characteristics and story indicators. The results show that the period ratios of the ELA-MSS system meet code requirements, and the system can effectively reduce story displacements and inter-story drift angles. Furthermore, adopting the ELA-MSS system alone or in combination with a braced frame system can significantly increase the maximum applicable height of modular structures in high seismic intensity regions. The FED-MSS system effectively reduces the inter-story drift angle of the module system and decreases the story shear forces in both the module and braced frame systems. The findings of this study provide a theoretical basis for the application and promotion of the ELA-MSS and FED-MSS systems in high-rise modular construction.