The invention discloses millimeter/terahertz wave imaging equipment and a reflector adjustment device thereof. The reflector adjustment device comprises a center support rod, a first pair of cams anda second pair of cams, a pitching rotating shaft and a swaying rotating shaft, and four peripheral oriented driving rods, wherein the center support rod is hinged to the back of a reflector; two Archimedes spirals define the circumferential edge of each cam; the pitching rotating shaft and the swaying rotating shaft rotate synchronously and are separately located in different planes perpendicularto the center support rod, the projections of the pitching rotating shaft and the swaying rotating shaft in the planes perpendicular to the center support rod intersect with each other perpendicularly, the point of intersection of the projections is located on the axial extension line of the center support rod, both ends of the pitching rotating shaft are connected to the centers of the first pairof cams, both ends of the swaying rotating shaft are connected to the centers of the second pair of cams, and the phase difference of arbitrary two adjacent cams is equal to a quarter of Pi; the fourperipheral oriented driving rods are parallel to and equally distanced from the center support rod, the first ends of the driving rods are in one-to-one correspondence to and in slidable connection with the four cams, and the second ends of the driving rods are in slidable connection with the back of the reflector. Through the reflector adjustment device, the trajectory of a wave beam, reflectedby the reflector, from an object to be detected is enveloped to be in a circle or ellipse with simple control.