Compared with centimeterwave radar, the millimeter wave radar has higher sensitivity while detecting nonprecipitating clouds, and thus the developed countries have conducted extensively cloud observation experiments using millimeter wave radar. In China, millimeterwave cloud radar is still at the developing stage due to the difficulty in designing radar system and manufacturing capability. Against this background, the advances in the Wband millimeter wave cloud radar are summarized in respect of the ground radar system, airborne radar system, and spaceborne radar system, and the system principle diagrams and performance parameters are analyzed in terms of antennas, transmitting circuits, receiving circuits and signal processing units. The radar echoes of nonprecipitation cloud detected by 94 GHz Galileo at Chilbolton Observatory are analyzed and the results show that the cloud and frog can be excellently detected, which can provide guidance for the Wband millimeter wave cloud radar design in China.