3D display device, 3D display system and method for displaying 3D images are disclosed in the present invention. The 3D display device comprises: a display screen; a backlight means including a pulse light source; and a drive means used to receive video signals which are based on a standard video transmission protocol, so as to control the display screen to display 3D images according to the video signals, and control the pulse light source to emit a backlight pulse in the form of pulse during a vertical blank of each frame period of the video signals, wherein the duration of the backlight pulse is shorter than that of the vertical blank. The degrading of light is avoided in the 3D display device and the efficiency of the backlight can achieve almost 100%.