An illumination device comprises a light transmitting shell, a light tight piece, an annular light emitting device and an annular light transmitting lampshade. A central area is arranged on the light transmitting shell. The light tight piece is arranged on the central area. The annular light emitting device is arranged on the position, corresponding to the central area, in the light transmitting shell. The annular light transmitting lampshade is arranged on the annular light emitting device and is provided with a first arc ring portion and a second arc ring portion, wherein the first arc ring portion is close to the light tight piece, the second arc ring portion is away from the light tight piece, and a refraction micro-structure area is formed on the inner surface of the first arc ring portion and is used for refracting light rays emitted by the annular light emitting device. The design that the refraction micro-structure area is formed on the portion, relatively close to the first arc ring portion of the light tight piece, of the light transmitting shell is adopted, the annular light transmitting lampshade can have a light ray refraction effect on the first arc ring portion so that light rays can be prevented from irradiating the light tight piece, the phenomenon that light rays are reflected or absorbed by the light tight piece can be avoided, and the illumination device can have the advantages of being high in light ray use efficiency and high in luminance.