Airbags is the most modern car introduced new technology of attention one of the devices. The airbag system mainly including sensor assembly, air, ignition, folding balloon, shall the nitrogen, warning lights, etc. When steam car by certain Angle ahead in the collision, put in front of the collision of the safety car sensors and central sensor, can detect the car suddenly to slow down, and the signal in the speed of 0.01 seconds to airbag system control computer. Through analysis on the computer after confirmation, detonated inside the balloon immediately electric hot firearms (i.e. electric detonators), and make it exploded. The process typically require 0.05 seconds. Ignition after detonated, solid nitrogen grain of rapid gasification, a large amount of nitrogen gasification, a large number of nitrogen immediately huff balloon, and in the powerful impact under the cover of the steering wheel airbag push aside and on safety. The main research contents have air bags, function, air bags, composition and the airbag principle of work.