Tempered glass is widely used in building structures, and its failure behavior and damage threshold under blast loading provide essential support for determining safety stand-off distances and explosion damage ranges. Investigating its failure mechanisms and damage criteria under blast shock waves therefore has important engineering significance. In this study, the mechanical behavior and failure mechanisms of tempered glass over a wide range of strain rates were investigated using a universal testing machine, a split Hopkinson pressure bar, and field emission scanning electron microscopy. Based on the mechanical test results, the material parameters of the Johnson Holmquist Ceramics (JH-2) constitutive model for tempered glass were determined through systematic analysis. Controlled blast loading tests were then conducted using a shock tube, and a finite element model was established to simulate the damage process. Comparisons between test observations and numerical results confirmed the validity of the calibrated constitutive parameters. Finally, a pressure-impulse damage curve was obtained to evaluate the damage threshold of tempered glass. The results provide a theoretical model and an analytical approach for the safety design and damage assessment of tempered glass structures.