6XXX age-strengthened aluminum alloys are extensively utilized across various fields, including construction, engineering machinery, and transportation, owing to their low density, good electrical conductivity and heat resistance, and excellent overall mechanical properties. Despite such widespread applications, there are no systematic computational frameworks for these alloys that are applicable across diverse processes, including microstructure simulations and performance predictions. Notably, to facilitate the material design and industrial production of 6XXX aged-strengthened aluminum alloys, the following steps are essential: analyzing the precipitation kinetics governing the mechanical properties of 6XXX aged-strengthened aluminum alloys, developing precipitation kinetics models, establishing corresponding strengthening models correlating microstructural features with key mechanical performance metrics, and performing mechanical simulations under standard service conditions to obtain stress-strain response characteristics. Accordingly, this study introduces a full-sequence computational model for 6XXX age-strengthened alloys based on the crystal plasticity theory. The proposed model is applicable to the investigation of several characteristics, including microstructure evolution, mechanical responses, and plastic deformations. Employing “structure-property” relationships as the entry points, the mechanical behaviors of 6XXX age-strengthened aluminum alloys are described through geometrical modeling and intrinsic relationship derivations. During this process, major factors influencing mechanical properties, including grain size and morphology, precipitation data and solid solution phases, and the characteristics of non-precipitation zones at the grain boundaries, are considered. The primary task involves computationally simulating the evolution of the size distribution and volume fraction of precipitated phases as well as variations in solid solution phase contents by sizing precipitated phases according to the grain size using the Kampmann-Wagner Numerical (KWN) method. According to the dislocation-density-based strengthening of materials, an age-strengthening model and a work-hardening model are established based on the interaction mechanism between precipitated phases and dislocations. The model tracks the evolution of yield strength and work-hardening properties with aging time. A method for computing the strength contribution from the precipitation-free zone at the grain boundary and a geometrical modeling strategy are proposed. The hardening model for 6XXX is selected based on the crystal plasticity finite element method, while uniaxial tensile plastic deformation is simulated to obtain stress-strain curves. The proposed multiscale analysis model of 6XXX age-strengthened aluminum alloys constructed based on the relationships among the alloy composition, aging process, microstructures, and mechanical properties of metallic materials provides a systematic framework for designing high-performance 6XXX age-strengthened alloys. It also highlights the key role played by computational mechanics in the development of new high-strength and high-toughness aluminum alloys, offering valuable insights. Furthermore, the analytical workflow of the study is extended to the crystal properties calculation package, which is universally applicable to studies on diverse age-strengthened materials, introducing its features and functions.