Abstract: In recent years, high power millimeter wave devices have been developed rapidly on the basis of further development and concept innovation of vacuum electronic technology , and with the progress of material science and micro-machining technology, including high power millimeter wave gyro traveling wave tubes, broadband traveling wave tubes, quasiterahertz traveling wave tubes, millimeter wave extended interaction klystrons, miniaturized traveling wave tubes and other types of new tubes. In the millimeter wave band, a series of remarkable achievements have been realized such as tubes with output power of 100 W ~100 kW or a wide bandwidth from 6 to 10 GHz. Using the progress in vacuum devices, combined with novel radar technologies, the researches on various radars including the millimeter wave mono-pulse precise measurement and target imaging radar, millimeter wave space combination passive phased array multi-target surveillance radar, millimeter wave miniaturized traveling wave tube active phased array multifunctional integrated radar and airborne sub millimeter wave video synthetic aperture radar have been implemented. In addition, significant breakthroughs in the applications of high power millimeter wave devices and key technologies of transmitters have been obtained. The multi-dimensional fine measurement and imaging of space targets have been successfully achieved by employing high power millimeter wave radars.