An IR controlling device includes a display panel, a number of IR emitters, a number of IR receivers, and a receiving controller. The IR emitters and the IR receivers are staggered under the display panel, and facing the display panel. The IR emitters are to emit IR beams in sequence, and the IR receivers are to receive the IR beams reflected by an external object. The receiving controller generates a plurality of response signals corresponding to the IR receivers. An IR processing unit receives the response signals, and determines a virtual position of the external object on the display panel. A controlling unit outputs a control signal and executes a corresponding function. A display processing unit receives the control signal and updates the content on the display panel.