Provided is a hologram display apparatus according to an exemplary embodiment of the present invention. The hologram display apparatus includes: a detector configured to detect a position of a viewer; and a spatial light modulation panel that modulates a light to display a hologram. Further, a grade is determined on the basis of the detected position of the viewer. An optical path switching unit refracts the light from the spatial light modulation panel with the determined grade. A laser source of the hologram display apparatus generates the light with a compensated output on the basis of the grade.