A three-dimensional display module includes a substrate, a display layer, a first electrode layer, a liquid-crystal layer, a second electrode layer, and a drive unit. The substrate has first electrodes and second electrodes. The display layer is disposed on the substrate and includes light-emitting elements. The first electrode layer is disposed on the display layer. The liquid-crystal layer is disposed on the display layer. The second electrode layer is disposed on the liquid-crystal layer. The drive unit drives the first electrodes and the first electrode layer to supply power to the light-emitting elements, such that the light-emitting elements generate light passing through the liquid-crystal layer to form a display image. The drive unit drives the second electrodes and the second electrode layer to produce an electric field on the liquid-crystal layer to change focal length of the liquid-crystal layer so as to control depth of field of the display image.