Abstract: Additive manufacturing technology has the advantages of large design freedom, no need for dies, and near net forming, so the technology has broad application prospects in aerospace, ocean engineering, petroleum engineering and other fields. However, due to the low heat conductivity and limitation of mold-filling capacity of high-strength alloys such as titanium alloys, their laser-formed components are prone to form defects such as pores, hot cracks, and cold cracks, which will reduce their mechanical properties. Recently, in order to dig out the micro-mechanism of forming defects, researchers have introduced several characterizing methods for analyzing the defects. In addition, on the basis of the results from the defects characterizations, technologies have been generated for repairing defects. In this article, we summarize the development of non-damaged three-dimensional characterizing technologies for forming defects, as well as the non-damaged defects repairing technologies. In the end, we also indicate the prospect of defects analysis and reparation for the components by laser additive manufacturing.