A complex blasting cap apparatus of an airbag for a vehicle includes: a detector detecting impact acting on a vehicle body during a vehicle accident; a controller receiving a signal detected by the detector, computing the received signal, and applying different voltages so as to operate an inflator depending on a pre-input impact force; and a complex blasting cap formed as integration of a first blasting cap which is operated by a control signal of the controller and is exploded by a first voltage signal applied from the controller and a second blasting cap which is connected to a circuit to which the first blasting cap is connected and is exploded by a second voltage signal applied from the controller.