Abstract: An element method to compute the burning surface of a three-dimensional propellant is proposed in this article. It is assumed that the propellant consists of a finite volume of elements and the burning surface consists of a finite area of elements. The propellant burning is considered to be the finite area of elements shoving in the normal direction, and then whether a volume of elements is burning out depends on the minimum distance between the volume of elements and the burning surface. The burning surface of the propellant is computed by its volume differential. This burning surface calculation method not only avoids stack math formulation derivation and calculation, but also avoids complex definition of standard geometry entities. The calculation results show that they can satisfy the precision requirements in actual engineering calculation. Because of its convenience and its ability for generalization to any three-dimensional propellants, this method has good prospects for actual application.

Key words: solid rocket motor, propellant, burning surface calculation, element method, minimum distance