Abstract: The interior ballistic calculation model of lamellar variable burning rate propellant was established based on the classical interior ballistic theory. Based on this model, the effects of the propellant thickness ratio of the outer layer to the total, the propellant burning rate ratio of the inner to outer layer, and the outer propellant force on the interior ballistic performance were studied. And the actual ballistic experiment was carried out on the sample of the lamellar variable burning rate propellant of a certain type of mortar. The results show that the model can effectively predict the interior ballistic performance of it. Meanwhile, it also shows that under the hypothesis of considering the bore pressure and initial velocity, the ratio of outer layer thickness to tablet thickness should be from 0.3 to 0.4 and the burning rate ratio of inner and outer layer should be about 0.2. The lamellar variable burning rate propellant meets the internal ballistic performance index of a certain type of mortar, and can be better used in this mortar.