A dental complex imaging system includes a base and chair on the base for allowing a patient sit; a base-mounted pole adjacent to the chair; a support part extending toward the patient; an expanding and contracting part pivotally coupled to the support part; a radiation generator that moves with the part for emitting radiation for an imaging mode selected from cephalography, panoramic radiography, and CT scanning; a detector disposed on the other side of the part and opposed to the generator; and a controller for reading imaging information, wherein the generator is disposed to slide to adjust a distance between itself and the detector according to the imaging mode while the patient sits on the chair.