A recently developed simulation method called corpuscular particle method(CPM) is studied by simulating the deployment process of airbag in static and dynamic conditions. An occupant safety analysis model is established to explore the effect of airbag and seatbelt involved with vehicle frontal crash test. Static deployment of folded airbag is simulated with the CPM and control volume(CV) methods, respectively. Comparison of simulation results indicates that the CPM is capable of simulating high speed gas flow inside airbag. By simplifying the behavior of gas molecules, the CPM is an efficient numerical analysis method to simulate the airbag deployment instead of the CV method. With the installation of folded airbag on occupant restraint system, vehicle frontal crash test is modeled in LS-DYNA, in which the folded airbag deployment emulated via the CPM. It is found that the CPM simulation results about the dummy head injury are in close proximity to the experimental data. Protection of airbag and seatbelt to in-position(IP) crew based on CPM are analyzed in details. It indicates that the protection of airbag to IP occupant’s head is better than that of seatbelt, which more durable on chest. Only combining with airbag and seatbelt can get the best protection.