The present disclosure relates to an organic light emitting display device that performs sensing and compensation for a characteristic value of a subpixel, and provide the organic light emitting display device that detects whether a sensing environment has a defect via transceiving a signal between a controller and a data driver before sensing is performed in a period in which the characteristic value of the subpixel is sensed, and controls sensing of the characteristic value of the subpixel according to detection of whether the sensing environment has a defect. According to the present disclosure, an error of sensing data due to a defect in the sensing environment may be prevented and an image abnormality due to compensation performed based on erroneous sensing data may be prevented, by detecting a defect in the sensing environment and stopping sensing of the characteristic value of the subpixel when the sensing environment has a defect.