In order to study the mechanical properties of human soft tissue, PlatSil? Gel was selected as the simulation material. Based on the polymer split Hopkinson pressure bar (PSHPB) experiments of polymers, combined with the Zhu-Wang-Tang (ZWT) constitutive model, and with the help of Fortran language, a new constitutive model is proposed. The VUMAT subroutine in ABAQUS software was used to redevelop the viscoelastic constitutive model of silica gel material. The validity of the constitutive model was verified by comparing the three-dimensional examples with the experiments. The results show that the finite element model developed by VUMAT subroutine is accurate, the simulation results are in good agreement with the experimental results, and the ZWT constitutive model can better describe the mechanical response of silicone material under strong dynamic load. The research results can expand the application of finite element software in the study of mechanical properties of biological soft tissue, and provide a theoretical reference for the analysis of soft tissue injury law.