In order to evaluate the influence of the bar on the killing probabilities of MEFP, numerical simulation of the process of the liner forming MEFP passing through the cutting bar was carried out with the Lagrangian method using LS-DYNA. The influence laws of the distance between bar and linear, the bar material and diameter of the bar on radial dispersion of MEFP were analyzed in this paper. Regarding radial dispersion of MEFP as index of damage probability on this basis, orthogonal optimization method was applied to analyze the primary and secondary relations of the three factors influencing the radial dispersion of MEFP. The results indicate that the diameter of bar is the main influence factor, and an optimum combination of every level of three factors affecting the radial dispersion of MEFP is gained.