Abstract: A nonlinear finite element model of a large commercial aero plane impact on the reactor cavity of high temperature gas-cooled reactor was established in this paper. In the calculation, the concrete reactor cavity adopted the damage plastic constitutive model of engineering reinforced concrete and the aero plane adopted Johnson-Cook constitutive model. By simulating the nonlinear impact process of the aero plane impact on reactor cavity of high temperature gas-cooled reactor, the impact load curve, displacement contour and damage of concrete in the reactor cavity under frontal and lateral impact conditions were obtained. Assessment results show that the overall damage of reactor cavity structure under impact condition is small, so the cavity can provide an important barrier function for important equipment inside it.