Abstract: The rupturing effect on a metal plate under the contact explosion of a linear explosive load is studied. On the basis of the plastic dynamical response of a rectangle, the critical rupture criterion is put forward, and the impulse criterion and the impulse formula of different parts of the linear explosive load are obtained. The explosive weight needed for different degrees of damage is calculated theoretically and the theoretical results are found to coincide well with the experimental data. The results can be used as a guidance or experimental evidence in the study on blasting rupture and in engineering use.