Even though there are extensively studies on penetration dynamics, these studies mainly focused on the structure response and penetration depth of projectile. Almost no charge stability theory theoretical analysis method in the process of penetration has yet been reported. This paper derived a novel theoretical analysis method of charge stability in the process of penetration, which is based on the assumption of plastic stress-strain deformation relationship of main charge, friction work, principle of thermal dynamics. The resistance function during penetration is based on the cavity expansion theory, using mass and monument equation, Hugoniot jump condition. The resistance forces are calculated with finite difference method and Newton′s Second law. The temperature rising between explosive-casing interfaces due to friction can be estimated with the input resistant force function. The novel theory shows that charge stability strongly depends on the maximum length of charge and overload characteristic of charge. In addition, the location of maximum temperature rising can be determined if the diameter of charge is given. The analytical results of this study provide the physical and geometry parameters, which can used as an important reference of charge design.