A car-attack defending apparatus includes a pressure-sensitive reaction module, an emergent airbag-inflation module, a crash barrier module, and an integral exterior unit module, wherein the pressure-sensitive reaction module has a pressure-sensitive setting and triggering mechanism, the emergent inflation airbag module has an emergent airbag expansion mechanism, and the crash barrier module has a crash-resistant steel plate. The car-attack defending apparatus can be disposed at entrances of specific buildings or restricted areas, so that at the moment a suspected car ignores warning and attempts to access the site, the emergent airbag expansion mechanism will be triggered, by the weight of the car, so as to expand the airbag simultaneously, and to stretch the crash-resistant steel plate to form a barrier. As such, the suspected car can be prevented from moving further, allowing checkpoint personnel a safe standoff distance from car bombs.