In order to study the influence of different fitness ratio of charge on jetting projectile charge, carry out numerical simulation of JPC charge influence. Use simulation software of AUTODYN to establish shaped charge model, carry out numerical simulation of JPC charge process, and analyze the influence principle of fitness ratio on JPC head speed, kinetic energy and explosion utilization ratio. The analysis results show that when the fineness ratio is larger than 1.4, the increase of charge-diameter ratio is little, the JPC head speed and kinetic energy significantly reduced. The results provide the reference for JPC warhead design and application.