To understand the influence of silicon content and ambient temperature on the burning rate of the Pb3O4-Si delay composition, the relationship among these three factors was investigated using the control variable method. A predictive numerical model that correlates the burning rate with the silicon content and ambient temperature was presented in this study. When the silicon content was varied from 10% to 50%, the burning rate and ambient temperature could be correlated using an Arrhenius-type temperature-dependence model. The burning rate and silicon content varied linearly when the silicon content was varied from 25% to 50%. The correlations among burning rate, silicon content, and ambient temperature were described through a numerical model. The proposed numerical model is useful for estimating the influence of the ambient temperature and silicon content on the burning rate in Pb3O4-Si systems.