无损检测（Nondestructive testing，NDT），是在不影响检测对象未来使用功能或现在的运行状态前提下，采用射线、超声、红外、电磁、太赫兹无损检测 等原理技术仪器对材料、零件、设备进行缺陷、化学、物理参数的检测技术。常见的有超声波检测焊缝中的裂纹等方法。中国机械工程学会无损检测学会是中国无损检测学术组织，TC56是其标准化机构。
NDT is divided into various of nondestructive testing, each based on a particular scientific principle. These methods may be further subdivided into various . The various methods and techniques, due to their particular natures, may lend themselves especially well to certain applications and be of little or no value at all in other applications. Therefore, choosing the right method and technique is an important part of the performance of NDT.
