The invention belongs to the technical field of automatic meal separating equipment, and particularly relates to a constant-volume automatic meal separating machine driven by a swinging air cylinder.A plurality of constant-volume distribution devices are mounted on the upper part of a rack of the automatic meal separating machine, and meal disc conveying devices arranged on the lower parts of theconstant-volume distribution devices are mounted on the rack; stainless steel containers of the constant-volume distribution devices are mounted on the rack, a vibration mechanism is arranged on thelower parts of the stainless steel containers, meal outlets in the lower parts of the stainless steel containers communicate with constant-volume split-charging mechanisms, and spiral conveying mechanisms are mounted on the stainless steel containers. The problems that in the prior art, constant-volume meal separating cannot be achieved, and the meal separating efficiency is low are solved, according to the constant-volume automatic meal separating machine driven by the swinging air cylinder, the meal separating quality is high, the occupied area is small, and distribution is uniform.