The invention discloses a system and a method for optical detection of a foot stand of a central processing unit. Through analyzing distribution of gray scale values in different regions, different binarization processing can be carried out, so that the influence of the external ray can be avoided, and a foot position of the foot stand of the central processing unit and the rest of the foot stand of the central processing unit can be clearly and accurately separated, and thus the technical effect of improving the optical detection efficiency of the foot stand of the central processing unit can be achieved.