Pressurized vessels and pipelines are widely used in the energy industry, military industry, scientific research and many other fields, and their transportation media are usually accompanied by flammable and explosive characteristics, so the importance of ensuring their safe operation is self-evident. The study of the safety of pressure vessels and pipelines has always been an important topic. The origin and latest achievements of the common standards and specifications based on the principle of "fit for use" at home and abroad were first introduced in the paper. The latest progress of key technologies used in defect assessment, as well as the research status of important factors influencing the assessment results, were also presented. Additionally, a brief overview of the application status of the assessment technology for defective containers and pipelines was provided. Finally, the existing problems in China's current defect assessment technology were highlighted, and suggestions for the development direction of safety assessments for pressure vessels and pipelines with defects were put forward.