he packaging buffer model of 2-DOF non-linear system with strong hysteresis was established and the vibration equations for the system were gained. After a series of transform, the state variables of the vibration differential equations were obtained. The response spectrum of non-linear system under the trapezoidal pulse shock was calculated using the fourth order variable step Runge-Kuntta method. The influence of mass ratio (1), stiffness (2) on the surface of response spectrum, which can fully reflect the dimensionless impact time (0) on the packaging system of law, was studied.