An optical coherence tomography device includes an OCT optical system a processor. The processor executes: an image generation processing of processing first OCT signals, and generating, based on the first OCT signals, a three-dimensional motion contrast image which is obtained by imaging a moving object in the scanning position a Doppler shift detection processing of detecting Doppler shift in a scanning position specified on the three-dimensional motion contrast image, the plurality of second OCT signals being detected at timings different from the timings when the plurality of first OCT signals are detected and a velocity obtaining processing of obtaining an absolute velocity of the moving object based on the Doppler shift detected by the Doppler shift detection processing and a three-dimensional structure of the test subject obtained from the three-dimensional motion contrast image generated by the image generation processing.
