An abnormality determination system applicable to a work machine includes: a stereo camera 22 mounted on a wheel loader having working equipment 10; a position data calculation unit 83 that estimates a position of the working equipment 10 in a captured image of the stereo camera 22 based on a posture of the working equipment 10 when captured by the stereo camera 22; and a determination unit 91 that determines whether the stereo camera 22 is normal based on the estimated position of the working equipment 10.