The invention provides a fatigue driving monitoring device and a fatigue driving monitoring method. The fatigue driving monitoring method comprises the steps of: 1) acquiring an acquired image; 2) converting the acquired image into a
YCbCr space, extracting a
skin color region and carrying out binarization to obtain a face rectangular frame; 3) scanning pixel points in the face rectangular frame, increasing
radius by taking each pixel point as a circle center, finishing the scanning until the pixel points exceeding a preset proportion in the scanning regions are white points or the scanning regions reach the boundary of the face rectangular frame, and regarding the
diameter of a maximum scanning regions as
pupil diameter; 4) and judging whether a driver is fatigued through monitoring the
pupil size in real time according to a PERCLOS
algorithm. The fatigue driving monitoring device and the fatigue driving monitoring method can form the face rectangular frame in the
YCbCr space quickly, simply and accurately, and detects the fatigue state of the driver through combining the real-time
pupil size monitoring with the PERCLOS fatigue detection method. The fatigue driving monitoring device and the fatigue driving monitoring method are simple and efficient, fast in operation speed and high in accuracy, and the monitoring process and result are not affected by the inclination angle of face.