Abstract: According to the results of the dynamic shear experiments of AerMet100 steel, a series of SHPB numerical experiments of the hat shaped specimens were carried out with ABAQUS/Explicit software, which simulated the adiabatic shear deformation process in the high strain rate loading condition. The numerical simulation results are well consistent with the experiments in the adiabatic shearing sensitivity, the critical speed and the width of the adiabatic shear bands. Based on the simulation results, a general relationship between the adiabatic shear sensitivity and velocity was analyzed, obtained the stress field, strain field and temperature field distribution. The results show that the carrying capacity of the shear region feature elements decrease with increasing loading rate, the critical velocity of shear band formation is 32 m/s or so, and the shear high temperature zone concentrates in microns strip area.