In order to improve the big burst height of the mask to the case conditions penetration ability, to the horn cover can charge formed together jet penetration homogeneous plates in the numerical simulation. Use AUTODYN-2D nonlinear dynamics analysis software Euler algorithm of the numerical simulation and experimental results contrast and analysis on the top of the change of the thick thin wall thickness horn wall thickness variation law to cover the formation of the penetration ability of the jet influence. The result indicates that, when medicine type cover wall thickness in range from 1.35 to 1.48 mm, wall thickness difference control in 0.03 ~ 0.05 mm in its penetration ability stability, can satisfy the design index.