An apparatus and method for compensating for color separation of an image in a holographic head-up display (HUD), caused by a change in characteristics such as a temperature or wavelength of a laser projector. An apparatus (200) for compensating for color separation of an image in a HUD includes a GPU (100); a video signal inputter (110); a temperature sensor (120); a controller (130); a memory (135); a panel driving unit (140) for outputting an image to a panel (160); a laser diode driving unit (150) for driving R, G, and B laser diodes (151), (152), and (153); a lens (70), and a screen (180). Accordingly, an image, the quality of which is degraded due to color separation of an image, may be improved.