Constitutive modeling is a crucial approach for understanding and predicting material behavior under ballistic impact, high-speed cutting, and hot metal deformation. To develop an appropriate constitutive model in this study, dynamic compression tests are conducted at various strain rates (700 s-1 to 1700 s-1) and deformation temperatures (298 K to 823 K) on C250 maraging steel by using the direct impact Hopkinson pressure bar technique. The experimental findings elucidate the coupled influences of strain rate and strain, as well as strain rate and temperature, on the dynamic compressive behavior of C250 maraging steel. To accurately predict the flow behavior of C250 maraging steel under different strain rates and deformation temperatures, this study develops modified Johnson-Cook models, which draw from both experimental data and the original Johnson-Cook model. Unlike the original model, the modified model accounts for the coupled effects of strain rate and strain, as well as strain rate and temperature. Consequently, the predicted flow stresses by the modified Johnson-Cook models are in excellent agreement with the observed flow behavior of C250 maraging steel, compared to the original model. Furthermore, verification tests that are used to evaluate the predictive capabilities of the model under new dynamic compression conditions confirm its ability to accurately predict the flow behavior of C250 maraging steel under various conditions.