在固体燃料冲压发动机（SFRJ）平均燃速理论分析基础上，通过数值摸拟，得出燃速与燃烧室直径和压强的指数表达式。得出了燃途与燃烧室相对长度、人口台阶相对高度和喷喉相对直径之间的定性关系，并比较了理论分析和数值模拟之间的差异。本文的研究对固体燃料冲压发动机的设计和实验有重要意义。 Based on the theoretical analysis of the average fuel injection speed of solid fuel ramjet engine (SFRJ), the exponential expressions of the combustion velocity and the diameter and pressure of the combustion chamber are obtained by numerical simulation. The qualitative relationship between the relative length of the combustion path and the combustion chamber, the relative height of the population step and the relative diameter of the throat is obtained, and the differences between theoretical analysis and numerical simulation are compared. The research in this paper is of great importance to the design and experiment of solid fuel ramjet engine.