The invention discloses a slab ingot feeding specification optimizing control method of an aluminum alloy hot roll, and relates to the technical field of metal pressure machining. The method includesthe following steps that A, conversion between the roll outer diameter and the roll weight is carried out; B, metal loss calculation is carried out in the machining process; C, the maximum multiple-length number of feeding is determined; and D, the slab ingot optimal feeding specification is determined according to the maximum multiple-length number. According to the method, through calculation ofthe above four steps, the optimized slab ingot feeding specification is obtained, and the problem of the batched finished product rate loss caused by the fact that the slab ingot feeding specification does not reach optimization when a coiled material is produced in an aluminum plate strip machining plant at present is solved.