By means of the 2-D simplified model,the dynamic process of the exploding tube of MFCG is simulated. The simulation results show that the expanding angle can be varied with the radial position(or different time) due to the radial velocity variation with the radial position(or different time). In order to compare the simulated expanding angle with the results of the experiments, the velocity should take an average over time(or position). The ending effect on the expanding velocity is given by simulation results and it may be useful to improve experimental results. The simulation results suggest that using high density metal material may reduce the sliding effect because the high density causes big ratio of radial velocity to axial velocity. The simulated expanding angles of 2-D model are c