A control method for image displaying applicable for use to a dual-side transparent display. The control method includes the following operations each required to be executed at least one time in a display period. The operations are: providing a left-eye signal of an image displayed on a first display surface of the dual-side transparent display, to a first side thereof; providing a right-eye signal of an image displayed on the first display surface of the dual-side transparent display, to the first side thereof; providing a left-eye signal of an image displayed on a second display surface of the dual-side transparent display, to a second side thereof; providing a right-eye signal of an image displayed on the second display surface of the dual-side transparent display, to the second side thereof; and configuring the dual-side transparent display to present a transparent state. A display system is also provided.