The process of folding and inflating the cylindrical airbag is complicated, and there are many inconveniences in using experimental methods to study its expansion process. Two different folding methods are proposed for the cylindrical airbag and the corresponding numerical analysis models are established respectively. The nonlinear dynamics software is used to study the dynamic application characteristics of the cylindrical airbag after being folded, which will affect the skin stress during the airbag expansion process. The factors of volume and internal pressure curve change are analyzed, and the influence of different folding methods and external environmental parameters on the dynamic characteristics of the cylindrical airbag is discussed. The results show that the two folding methods have their own advantages in storage space and material strength. In addition, in the environmental parameters, the external pressure has a greater impact on the stable state of the airbag after expansion, while the temperature has no obvious effect.