A field emission display includes a panel and a control unit. The panel has a number of pixel units. Each of the pixel units has at least one fluorescent layer. The control unit which electrically connects to the pixel units receives an objective image. The control unit further selects a part of the pixel units corresponding to the objective image, divides the part of the pixel units into a number of pixel unit groups, and scans the pixel unit groups to make the plurality of pixel unit groups sequentially work such that the panel displays the objective image.