The utility model provides an illuminating set and an image detector thereof. The illuminating set comprises a plurality of LED lamps and an arch structure; the arch structure comprises an arch cover and bottom plates connected to the bottom end of the arch cover; the LED lamps are disposed on the inner sides of the bottom plates; the arch cover is provided with a slit which deviates from the center line. According to the illuminating set, light from the LED lamps is reflected by the arch structure and passes out from the slit, shade of each sampled image can be limited, and the images can be better recognized. Especially, shade of cigarette labels of two types of Huang He Lou cigarettes can be well eliminated.