The present invention relates to the field of optical lenses and provides a camera optical lens. The camera optical lens includes, from an object side to an image side: a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; a seventh lens; and an eighth lens. The camera optical lens satisfies following conditions: 4.00≤f1/f≤7.50; f2≤0.00; and 1.55≤n4≤1.70, where f denotes a focal length of the camera optical lens; f1 denotes a focal length of the first lens; f2 denotes a focal length of the second lens; and n4 denotes a refractive index of the fourth lens. The present invention can achieve high optical performance while achieving ultra-thin, wide-angle lenses having a big aperture.