The deformation resistance were researched during the projectile sabot impinging on the conic-chamber at a high speed in the interior ballistics phases . The calculational modeling of interior ballistics was set up based on the special structre of conic-chamber and projectile. The p-l curve, v-l curve and v-t curve were obtained with modeling by MATLAB. These curves were similar to those calculated with the correction subordinate method. And the results were coinsident with the experiment results. which proves the method to be feasible.