Abstract: The structural shape of selective laser melting (SLM) parts is complex. Conventional radiographic testing techniques are prone to blind spots in the detection of structurally complex parts.Industrial computerized tomography (CT) technology can achieve overall inspection of parts, and there is no blind spot for complex parts. At present, the design of industrial CT reference blocks lacks relevant experimental verification basis. Therefore, aiming at the representative problem of reference blocks, this paper carried out a study on the influence of defect forms, different locations of defects of the same size, cylindrical roughness, and the forming method on the detection results of industrial CT. The research results indicated that through hole defects were easier to detect than blind holes. The different locations of defects of the same size had no obvious influence on the detection of cavity defects, but the closer the defect was to the center, the greater the impact of circular artifacts. The surface roughness of the test block and the forming method of the test block matrix had no obvious influence on the detection of cavity defects.