<p>In limestone aggregate mining blasting, the powder generation rate (particle size &lt; 4.75 mm) reaches 15–25%. Conventional empirical models overlook the prediction of the powder zone, making it difficult to optimize blasting designs for effective powder control. Therefore, a method based on a dynamic strength threshold for predicting rock mass fragmentation zoning is proposed. The dynamic impact tests on limestone under medium–high strain rates are conducted using SHPB, which reveals strain rate-dependent relationships of dynamic compressive strength and fragmentation energy density and establishes a critical stress threshold criterion for powder generation. Subsequently, a theoretical predictive model for blasting-induced damage zoning is developed by coupling the dynamic compressive strength degradation model with stress wave attenuation laws, from which theoretical formulas for the powder zone range are derived. In addition, numerical simulations and field tests confirm the reliability of the model. The results showed that the dynamic compressive strength of limestone follows an exponential relationship with strain rate, while the fragmentation energy density presents a logarithmic correlation with strain rate. The critical stress threshold for powder generation in limestone is identified as 341.36 MPa. Compared to conventional models, the proposed method enables quantitative prediction of powder generation by incorporating dynamic strength threshold criteria and strain rate correction mechanisms, providing a theoretical basis for optimizing blasting parameters to reduce powder production.</p>