The present disclosure provides an organic light emitting display device including a display panel in which a plurality of Sub Pixels defined by a plurality of Data Lines and a plurality of Gate Lines are arranged, and a control method thereof. The organic light emitting display device includes a temperature sensor configured to detect a temperature of the display panel, and a gate pulse modulator configured to modulate a voltage in a falling section of a scan signal provided to the plurality of GLs, in real time in accordance with the temperature. Accordingly, it is possible to prevent data from being mixed with each other, so that a clearer image can be realized, thereby improving the image quality.