###### Abstract  
Under the impetus of achieving global sustainable development goals, the civil construction industry is accelerating its transition towards high-quality, green, and low-carbon practices. Prefabricated, modular building technology has become a key tool due to its advantages in energy conservation, emission reduction, and shortened construction periods. However, existing research on the seismic performance of prefabricated, modular, reinforced concrete column-beam (RCS) composite structures often focuses on the construction form of beam-column joints, paying less attention to the impact of floor slabs on the seismic performance of joints during earthquakes. This may make joints a weak link in structural systems' seismic performance. To address this issue, this paper designs a prefabricated, modular RCS composite joint considering the effect of floor slabs and uses the finite element software ABAQUS 2023 to perform a quasi-static analysis of the joint. The reliability of the method is verified through comparisons with the experimental data. This study examines various aspects, including the joint design and the material's constitutive relationship settings, focusing on the influence of parameters, such as the axial compression ratio and floor slab concrete strength, on the joint seismic performance. It concludes that the seismic performance of the prefabricated, modular RCS composite joints considering the effect of floor slabs is significantly improved. Considering the composite effect of the slabs, the yield loads in the positive and negative directions for node FJD-0 increased by 78.9% and 70.0%, respectively, compared to that of the slab-free node RCSJ3. The ultimate bearing capacities improved by 13.2% and 9.98%, respectively, and the energy dissipation capacity increased by 23%. Additionally, the variation in the axial load ratio has multiple effects on the seismic performance of the joints. Increasing the slab thickness significantly enhances the seismic performance of the joints under positive loading. The bolt pre-tensioning force has a crucial impact on improving the bearing capacity and overall stiffness of the joints. The reinforcement ratio of the slabs has a notable effect on the seismic performance of the joints under negative loading, while the concrete strength of the slabs has a relatively minor impact on the seismic performance of the joints. Therefore, the reasonable design of these parameters can optimize the seismic performance of joints, providing a theoretical basis and recommendations for engineering application and optimization. f 2025 15 May 2025 5 June 2025 15 May 2025  
towards industrialization and greening. Prefabricated, modular construction technology, with its significant energy-saving and emission reduction benefits, as well as advantages in project duration, has become an important vehicle for new building industrialization [1]. Some studies show that the construction industry accounts for a significant proportion of global terminal energy consumption, and that the level of carbon emissions during the construction phase is also relatively high, which creates an urgent need for the promotion of prefabricated technologies [2]. Among these, the reinforced concrete column-beam (RCS) composite structure achieves a synergistic balance between concretes' high compressive strength and steels' superior tensile properties through optimized material configuration [3]. The lifecycle analysis of these materials shows that compared to the traditional cast-in-place frames, this structural form has significant environmental advantages, effectively reducing embodied carbon emission levels. Its modular construction characteristics also demonstrate considerable potential in improving work efficiency.