The disclosure discloses a millimeter wave security inspection apparatus and a method for inspecting human or article. The apparatus includes: a door device including a first door and a second door arranged in a stacked mode and each made of a material allowing a millimeter wave to penetrate therethrough; a millimeter wave transceiver arranged between the first door and the second door and including an millimeter wave transceiving antenna array configured to transmit and receive a millimeter wave signal to and from an entrance side and an exit side of the door device; and a linear driver to which the millimeter wave transceiver is connected to be movable relative to the door device, so as to scan a first side of an object positioned at the entrance side and a second side of the object opposite to the first side positioned at the exit side.