Objective In order to investigate the dropping impact characteristics of a cantilever beam critical component, a cubic nonlinear packaging system was taken as the study object. Methods A dropping impact dynamics model was established for the critical component packaging system, and the Runge-Kutta method as well as the finite difference method were applied for numerical analysis. Results The example showed that the change in displacement response of the critical component was insignificant along the length direction, while the acceleration changed noticeably. And, the maximal acceleration response and displacement response occurred at the free end, while the maximal stress occurred at the connection between the product and the critical component. Conclusion Whether the maximal stress of the critical component surpasses its elastic limit could be used as a judgment criterion of product failure.