Abstract: Based on the analysis of the industrial CT technology principle and on the understanding of forming mechanism and characteristics of typical defects of the laser melt additive manufacturing, the contrast specimens with simulated defects were designed with the help of laser melt additive manufacturing process. Industrial CT tests were performed for the contrast specimen, specimens with simulated defects and the actual samples, and test results have shown that the industrial computed tomography technology can effectively detect typical defects of products by laser melting additive manufacturing, such as holes and cracks, and the CT is an effective detection method for quality assurance of laser melting additive manufacturing product.