The invention provides a single-station planar array millimeter-wave imaging device and method. According to the method, a millimeter-wave sweeping source is utilized to generate a linear frequency modulation millimeter-wave signal, and the millimeter-wave detection signal is radiated to the space through a receiving and transmitting component, an electronic switch array and a one-dimensional array antenna; the one-dimensional array antenna forms an equivalent two-dimensional planar array under the joint action of the electronic switch array, a horizontal guide rail and a servo motor; a data collection card simultaneously collects medium-frequency information of the receiving and transmitting component and antenna position information obtained through a grating ruler, so that antenna positioning precision is improved; and an imaging method with loss compensation is adopted in a data processor, so that imaging quality is improved.