A cholesteric liquid crystal (LC) composite display device includes a light absorbing substrate, a first and second transparent substrates, a light supplement module arranged between the light absorbing substrate and the first transparent substrate, a control module, a first and second electrode layers respectively formed on the first and second transparent substrates, a first cholesteric LC layer sandwiched between the first and second electrode layers, and a first light absorbing layer disposed on the second transparent substrate. The projection of the first light absorbing layer on the horizontal plane and the projection of the light supplement module on the horizontal plane are arranged in a misaligned manner. The control module is provided for controlling the light supplement module according to the brightness signal. Thereby, when the external brightness is low, the light supplement module enhances the displaying brightness of the cholesteric LC composite display device to meet the usage requirements.