Aiming at the matching relationship between various parameters in the gas-solid in-situ synthesis of copper azide, we establish a two-dimensional shrinking core model to simulate the crystal growth mechanism of in-situ synthesis of copper azide and dynamic process. The relationship between the reaction rate of azide porous copper and the solid conversion rate and the diameter of precursor, porosity, charge height and reaction time have been obtained. At the same time, in order to verify the reliability of the model, a set of porous copper precursors with a porosity of approximately 80% and a height of 1mm and particle diameters of 50, 100, 200 and 500 nm are selected for the analysis of copper azide. Results show that the experimental data of the four different azide products are consistent with the simulated, and the maximum deviation is only 2.1%.