A 3D display system for displaying a 3D image includes a tracking unit, a pixel panel, a grating array, and a control unit. The tracking unit is configured to determine a spatial position of a viewer of the 3D display system. The pixel panel contains alternatingly arranged display units from two or more view images of the 3D image, and the grating array is coupled to the pixel panel to separate light from the view images from the pixel panel. The control unit is configured to adjust certain parameters of the grating array such that a maximum width of horizontal projection of edges of adjacent display units through the grating array is less than or equal to a inner-eye distance, and a minimum width of horizontal projection of two edges of a single display unit through the grating array is greater than or equal to an outer-eye distance.