Numerical simulation is a vital tool for studying the dynamic characteristics of rock, with the accurate determination of models and parameters being the key to ensuring the reliability of simulation results. Among the 34 parameters of the RHT model, 19 parameters can be obtained through experimental and theoretical calculations, but the remaining 15 are challenging to determine. Nineteen basic parameters of anhydrite were obtained through experimental analysis and theoretical calculation to identify the model parameters suitable for anhydrite. Furthermore, the LS-DYNA performed SHPB simulation tests on the 15 challenging parameters. The sensitivity of stress-strain curves to these parameters was compared, and the values were optimized. Parameters with high sensitivity were identified through orthogonal testing. Finally, simulation results were compared with laboratory test results. The findings indicate that RHT parameters B, , n, D₁, n_f, P_comp and N have minimal impact on the stress strain curve, while parameters A, , , Q₀, , ξ, and A_f significantly influence the curve. Furthermore, the parameters with a significant impact on the stress-strain curve were determined by orthogonal tests, and the RHT model parameters fitting the SHPB impact test curve were obtained. Under varying loading strain rates, the dynamic stress-strain curves and failure patterns of anhydrite simulation tests were consistent with laboratory tests, verifying the suitability of the model parameters for anhydrite.