The invention belongs to the technical field of organic photoelectric displaying, and in particular provides a single-layer multi-electrochromism device and a preparation method thereof. The device has a simple structure and comprises four parts, namely an anode transparent conductive substrate, a packaging film, an electrolyte-mixed electrochromic material layer and a cathode transparent conductive substrate, wherein conductive layers of the anode transparent conductive substrate and the cathode transparent conductive substrate are partially etched. When the device works, an electrochromic material generates different electrochromism in four areas, namely an area only having an anode conducting layer, an area only having a cathode conducting layer, an anode and cathode conducting layer superposed area and an area without the anode conducting layer and the cathode conducting layer, thereby achieving a multi-electrochromism device. The single-layer multi-electrochromism device provided by the invention cannot only implement a change of various colors under different voltages, but also can simultaneously implement the change of various colors under the same voltage. A preparation process of the device is simple, and the materials are strong in universality.