The invention provides a miniaturized millimeter wave imaging radar device, and the radar device includes a monolithic microwave integrated circuit and an antenna radiation unit. The monolithic microwave integrated circuit includes a multipath transmission system and a multipath receiving system, and the antenna radiation unit is composed of a transmission antenna radiation unit and a receiving antenna radiation unit; the transmission system includes a multipath power amplifier module, a multipath electronic phase shifter module and a millimeter wave signal generation module, and the receivingsystem includes a multipath millimeter wave receiving module and a multipath intermediate frequency amplification module; and a signal output by the multipath power amplifier module is radiated to space through the transmission antenna radiation unit, the receiving antenna radiation unit transmits the signal to a low-noise amplifier, the low-noise amplifier transmits a received signal to a mixer,and the mixer transmits the processed signal to the multipath intermediate frequency amplification module. The millimeter wave imaging radar device provided by the invention adopts the monolithic microwave integrated circuit, a structure is simplified, and the volume is reduced.