Benzocyclobutene (BCB)-based resins have garnered considerable attention because of their remarkable dielectric properties and thermal stability. However, in molecular dynamics (MD) simulations, progress in BCB-based resin research has yet to keep pace with experimental advancements, resulting in a shortage of theoretical underpinnings at the molecular level. This study focuses on a novel homopolymer, poly(2-(4-benzocyclobutenyl)-divinylbenzene(DVB-S-BCB)), and devises an interactive methodology suitable for BCB-based resins. We implemented a Python script for the joint relaxation method to construct a three-dimensional model of the cured polymer using MadeA and LAMMPS. We conducted MD simulations to investigate how the cross-linking degree and resin molecular weight influence the dielectric properties of the cured polymer. Furthermore, we analyzed the thermodynamic properties through simulation. The results illustrate that augmenting the cross-linking degree and resin molecular weight results in a higher cross-linking density and reduced free volume, thereby increasing the dielectric constant of the resin. The cross-link density does not increase indefinitely with molecular weight, and after a certain threshold is reached, it cannot have a significant effect on the dielectric constant. The degree of cross-linking exerts a more pronounced impact on the dielectric constant than the molecular weight of the resin. In addition, the simulation results denote the excellent thermodynamic properties of the cured polymer. This study also examines the dielectric and thermodynamic properties of the resin samples that were experimentally prepared. The obtained data successfully confirm the reliability of the simulation results. This study offers novel insights for future simulation research on benzocyclobutene-based resins. Additionally, it provides theoretical support for exploring experimental work on low-dielectric materials in the electronic field.