Provided is a three-dimensional (3D) display device and display method. The 3D display device includes a zoom lens unit; and a two-dimensional display unit, which is located on a side of the zoom lens unit, where a distance between the two-dimensional display unit and the zoom lens unit is less than a minimum focal length of the zoom lens unit; where the two-dimensional display unit is used for displaying multiple two-dimensional images of a three-dimensional picture, and the multiple two-dimensional images corresponds different depth of field. When the two-dimensional display unit displays the two-dimensional images corresponding to different depth of field, the zoom lens unit has a different focal length for the depth of field corresponding to each of the plurality of two-dimensional images. The display time of the three-dimensional picture is less than visual persistence time.