A mirror display module including a first substrate, pixel units, a second substrate, a display medium layer, a reflection pattern, a third substrate, an electrochromic material layer, a first transparent electrode, and a second transparent electrode is provided. The pixel units are disposed on the first substrate. The second substrate is disposed opposite to the first substrate. The display medium layer is located between the first substrate and the second substrate. The reflection pattern is located between the second substrate and the display medium layer. The reflection pattern has a plurality of openings, and the plurality of openings is overlapped with at least a portion of the plurality of pixel units. The second substrate is located between the third substrate and the first substrate. The electrochromic material layer is located between the third substrate and the second substrate. The first transparent electrode is located between the third substrate and the electrochromic material layer. The second transparent electrode is located between the electrochromic material layer and the second substrate.