When the length of an annular liquid film in a circular pipe exceeds a critical length under zero gravity, the liquid film breaks into several lobes periodically, and plugs are formed. The dynamic behavior of the interface deformation of the liquid film under zero gravity was investigated using a three-dimensional simulation based on the finite difference method. For concentric gas-cores with various diameters, the numerical results of the average distance between lobes were in good agreement with those of the linear stability analysis. For eccentric gas-cores, the average distance between lobes was longer in the numerical simulation due to the eccentricity of the gas-core (the lack of uniformity of the film thickness at the transition to zero gravity) and the combination between adjacent lobes during the interface deformation. The numerical results of the distance were in reasonable agreement with those of our drop-shaft experiments under microgravity.