An illumination equalizing device includes a polygonal rotary column disposed in a sealed space, equipped with light sources, and rotatable at specific angular intervals, light sources radiating light onto an image test member attached to a wall of the sealed space for testing a digital image, the light sources mounted on side surfaces of the polygonal rotary column, illuminometers measuring illumination values of light radiated onto the image test member, and a rotary column control unit rotating the polygonal rotary column at set angular intervals so that the illumination values measured by the illuminometers are equalized. A method for equalizing the illumination of light sources for a digital image test member, and an apparatus and method for testing the color of a digital image uses the illumination equalizing device.