Abstract: To clarify the complex mechanical behavior during clamping of thin-walled main load-bearing structural component material consisting of cast aluminum 114 and IPA laminated layers bonded with RTV162 adhesive, the mechanical properties of this specific composite structure under quasi-static and dynamic compression were investigated. Quasi-static and dynamic compression tests were conducted at room temperature using an electronic universal testing machine and a split Hopkinson pressure bar (SHPB) apparatus, respectively, to obtain the stress–strain curves of the material at various strain rates. Based on the experimental data, the parameters of the Johnson–Cook constitutive model were calibrated by means of least squares fitting, thereby establishing a constitutive model applicable to the structural material. To verify the validity of the proposed constitutive model, finite element numerical simulations were further performed, and the simulated results were compared with the experimental data. The results indicate that the established Johnson–Cook constitutive model can accurately characterize the mechanical behavior of the material across different strain rates, and the stress–strain curves obtained from the numerical simulations are in good agreement with the experimental results, with an average global relative stress error of less than 5%, thereby fully validating the reliability of the calibrated parameters. The development of this constitutive model provides essential material model support for the strength analysis and failure prediction of thin-walled primary load-bearing structural components, and is of significant value for engineering applications.