A light emitting diode display system includes a first LED display module, a second LED display module, a control module, and a first driving module. The first LED display module includes a plurality of LED units for displaying an image. The first driving module is electrically connected to the control module and the first LED display module. The control module provides a plurality of control signals corresponding to the image to the first driving module for driving the LED units of the first LED display module, and displaying the image on the second LED display module. The image of the first light emitting diode display module is determined by a user according to the image displayed on the second light emitting diode display module.