The invention discloses a production line of liquid additive premixed feed. The production line comprises a general distribution box and a first conveying belt and further comprises a bottle unscrambler, a filling machine, a cap screwing machine, an aluminum foil sealer, a labeling machine, a boxing machine and a stacking machine which are sequentially arranged in the conveying direction of the first conveying belt, and a first photoelectric sensor and a second photoelectric sensor are arranged between the bottle unscrambler and the filling machine as well as between the filling machine and the cap screwing machine correspondingly; and the production line further comprises a dosing device connected with the filling machine through a pipeline, and the first conveying belt, the bottle unscrambler, the filling machine, the cap screwing machine, the aluminum foil sealer, the labeling machine, the boxing machine, the stacking machine, the dosing device, the first photoelectric sensor and the second photoelectric sensor are electrically connected with the general distribution box. According to the production line, automatic production of the liquid feed is achieved, the influence of a production link on products is reduced, and the production efficiency is improved obviously; and the oxygen content of the products is low, and the guarantee period of effective compositions is long.