Objective renal tissue is often damaged by impact load in traffic accidents. Understanding the dynamic mechanical properties of kidney is of great significance for injury assessment and safety protection in accidents. Methods I Based on CT images, the kidney finite element (FE) models with different ages were constructed. The renal dynamic impact test was reconstructed using the developed FE models. The effects of kidney material constitutive parameters, kidney tissue structure, kidney size, impact position and impact velocity on injury severity were investigated. Results Under the same impact condition, the kidney stress decreases with the increase of kidney mass and increases with the increase of impact velocity. The renal capsule has a certain energy absorption effect which reduces the stress of the kidney. When the kidney was impacted, the Renal stress of side impact was significantly higher than that of frontal impact. Conclusion Compared with viscoelastic constitutive model, Mooney Rivlin material constitutive model is more suitable to evaluate kidney injury severity when using FE method. The kidney injury decreased with the increase of kidney mass. With the increase of the impact velocity, the kidney injury severity increased significantly. The existence of renal capsule will reduce renal injury to a certain extent, so the existence of renal capsule structure must be considered in renal finite element modeling. The lateral of the kidney is more vulnerable to impact damage.