Geopolymers are promising sustainable materials for structural and geotechnical applications. However, their pronounced multiscale structural heterogeneity complicates the direct linkage between atomistic mechanisms and macroscopic mechanical performance. In this study, a hierarchical multiscale molecular dynamics (MD) —peridynamics (PD) framework is developed, in which PD serves as an intermediate bridge connecting MD simulations with experimental observations of geopolymer mechanics. This framework enables the transfer of material characteristics across scales and allows the effects of Si/Al ratio and porosity on mechanical behavior to be systematically evaluated. The simulations indicate that Young’s modulus decreases with increasing Si/Al ratio, while the maximum tensile strength is achieved at a Si/Al ratio of 2. Under zero-porosity conditions, the PD-predicted Young’s modulus closely matches the MD results, whereas in the presence of porosity, the PD predictions fall within the experimental range. These findings demonstrate that PD effectively extends the applicability of MD simulations to the mesoscale and provides a practical multiscale framework for the design and optimization of geopolymers.