Abstract: The theory of interior ballistic course of solid traveling charge was studied to increase the initial velocity of a big caliber gun. Based on the good results in tests and numerical simulations in the 30 mm gun of traveling charge, a zero-dimensional interior ballistic model of solid traveling charge was developed by keeping the fire data and charge conditions of the 100 mm gun same and considering the projectile mass variable. The developed model was used to numerically analyze the interior ballistic performances and to explore the effects of traveling charge mass, ignition lag time and charge power shape on the interior pressure and initial velocity of the gun. Computed results can provide an instruction for the design and experiment of the 100 mm gun of traveling charge.