An electrowetting display device includes an electrowetting display panel and an illumination unit. The electrowetting display panel includes two or more different optical color-converting liquid layers and a plurality of light-shielding liquid layers. The two or more different optical color-converting liquid layers are able to convert the light source generated by the illumination unit into light beams having two or more different colors of desired grey scales. The light-shielding liquid layers can be driven to change the transmittance of display regions so as to implement switch between transparent display mode, non-transparent display mode and semi-transparent display mode.