THz wave technology has a broad application prospect in the fields of biomedical, material science, astronomy and military communication. The operation principles of several vacuum electronic devices which can generate THz wave are presented. The bottleneck problems met with in their development are described. The superiorities for using vacuum electronic devices to generate THz wave are derived. The current research and application status of the THz vacuum electronic devices at home and abroad is presented and the prospects of THz wave generation technologies of vacuum electronic devices are given.