A composite imaging apparatus for dental diagnosis, wherein dental diagnosis for teeth/periodontal diseases and orthodontics can be simply done even with an imaging apparatus, and a patient's head portion can be automatically rotated according to image taking directions so as to simplify radiography, save radiography time, and minimize X-ray exposure. The apparatus includes a rotary arm horizontally rotating in left and right directions in order to take an X-ray image of teeth, jawbone and alveolar bone of a patient; a support frame vertically moving with a proper range according to a height of the patient, supporting and enabling the rotary arm to be fixed and horizontally rotate; and an object moving device formed on the base so as to move up and down a for certain range, reciprocate in forward and backward directions, horizontally rotate in forward and reverse directions while the patient is sitting thereon, and facilitate radiography.