Disclosed is an organic light-emitting display device and operating method thereof that may include an organic light-emitting diode, a first transistor controlled by a sensing signal and connected to a data line, a second transistor controlled by a scanning signal and connected to the data line, and a driving transistor having first to third nodes, wherein a reference voltage is applied to the first node through the first transistor, a data voltage is applied to the second node through the second transistor, and the third node is connected to a driving voltage line.