Abstract: Compared with the conventional plane wave, the vortex electromagnetic wave carrying orbital angular momentum has a unique spiral phase structure and orthogonal mode characteristics to obtain more information, and thus receives extensive attention in radar detection. The new dimensional information brought by the orbital angular momentum modulation provides conditions for new system radar imaging. In addition, the rotational Doppler effect observed by vortex electromagnetic waves can obtain the movement information perpendicular to the distance direction, which is difficult to detect by plane waves, and make up the deficiency of plane wave radar detection. Basic concepts, characteristics, and common generation methods of vortex electromagnetic waves are introduced firstly. Then basic principle of vortex electromagnetic wave imaging based on a uniform circular array is introduced, and basic principle of using vortex waves for rotational Doppler detection is briefly derived, and the research progress of vortex waves in radar imaging and rotational Doppler detection is summarized. Finally, future research trends are prospected.