Abstract: To study the dynamic mechanical properties of K418B superalloy, commonly used in aeroengines within a wide range of strain rates and temperatures, high-temperature mechanical properties experimental systems at different strain rates was utilized, and compressive mechanical properties of K4188 superalloy were tested at different strain rates (quasi-static, 100 s⁻¹, 1 000 s⁻¹ and 5 000 s⁻¹) and at different temperatures (room temperature, 400 ℃, 600 ℃, 950 ℃). The stress-strain curves of the material were obtained. Based on the experimental results, the effects of temperatures and of strain rates on the mechanical properties and on the failure modes of K418B superalloy were analyzed. The results show that the flow stress decreases with the increase of temperatures and the strain hardening effect decreases with the increase of temperatures under quasi-static compressive loadings. Under dynamic compressive loadings, the flow stress does not decrease significantly when the plastic deformation is small below 600 ℃, and when the temperature rises to 950 ℃, the flow stress decreases significantly from the beginning of the deformation. With the increase of temperatures, the strain rate strengthening effect becomes more obvious. Under compressive loadings, the shear crack of 45° appeared in the specimen. The oxidation corrosion and deformation of the specimen are intensified with the increase of temperatures. Based on the experimental data, a modified Johnson-Cook constitutive model was established, and a parameter identification method for the constitutive model based on particle swarm optimization algorithm was proposed. Through parameter optimization, the mechanical performance prediction accuracy of K418B superalloy within a wide range of strain rates and temperatures was significantly improved.