The application of large-capacity automotive power batteries puts forward higher requirements on the safety test and evaluation technology. In this study, a series of mechanics experiments on a large-capacity prismatic lithium-ion battery (PLIB) cell, including quasi-static compression experiments and dynamic experiments at different speeds, were performed to investigate the mechanism involved in typical severe collision conditions of electric vehicles, such as side pillar collision, bottom ball impact, and frontal collision. The failure critical point of lithium-ion battery cell is obtained based on the record of test failure conditions. The finite element simulation on the platform Ls-Dyna is conducted to establish a numerical model of the selected large-capacity lithium-ion prismatic battery, where the constitutive behavior of the shell and jellyroll is determined through the experiments. The compression results of the finite element model have shown a good agreement with the experimental data, which demonstrates its effectiveness and accuracy. This research provides an effective and practical procedure to judge the safety of lithium-ion batteries after collisions and can be extended to the prediction and protection design of battery packs.