Abstract: Through the research on the technology of coating the ignition powder in the bridge wire area of the ignition powder head, it is found that when a certain concentration of ignition powder is used to coat the powder head, shrinkage holes will appear around the bridge wire, and the diameter of the shrinkage hole is 200 μm. Shrinkage cavities may have an impact on the reliability of the ignition of the pyrotechnic charge. The micro-focus CT imaging technology is used to detect the shrinkage cavity formed by the coating head. In addition, on the basis of the micro-focus CT imaging detection, the modulation concentration of the ignition powder is changed to improve the coating process of the head, that method can effectively avoid the head forms shrinkage holes which affects the ignition reliability of the product.