An automatic delivery system for a washing machine, comprising a water box provided with a water outlet configured to be communicated with a washing barrel of a washing machine, a main water inlet pipeline and a detergent delivery pipeline, wherein the water box is integrated with the main water inlet pipeline and the detergent delivery pipeline is communicated with the main water inlet pipeline and a washing additive box, wherein the automatic delivery system further comprises a distribution box arranged inside the water box, the distribution box being internally provided with at least one installation cavity for accommodating a washing additive box; the washing additive box being installed in the installation cavity, the washing additive box being a closed box body with a cavity for accommodating washing additive, and being provided with a unidirectional ventilation structure and a liquid outlet, the liquid outlet being open when the washing additive box is communicated with the detergent delivery pipeline, and the liquid outlet being close when the washing additive box is disconnected with the detergent delivery pipeline; and a negative pressure extraction mechanism, comprising a Venturi tube arranged in the main water inlet pipeline, the washing additive being drawn out of the washing additive box via the detergent delivery pipeline and delivered into the washing barrel through the main water inlet pipeline by a negative pressure generated by water flow through an outlet of the Venturi tube, wherein the outlet of the main water inlet pipeline is communicated with a water outlet of the water box, wherein, the washing additive box is provided with a liquid outlet device, the liquid outlet device comprises an on-off valve arranged on the liquid outlet of the washing additive box and a suction device arranged in the washing additive box, the suction device is a hollow tubular structure, a flow channel is formed inside the suction device, and one end of the flow channel faces a bottom wall of the washing additive box, and another end of the flow channel is communicated with an inlet of the on-off valve. a water box provided with a water outlet configured to be communicated with a washing barrel of a washing machine, a main water inlet pipeline and a detergent delivery pipeline, wherein the water box is integrated with the main water inlet pipeline and the detergent delivery pipeline is communicated with the main water inlet pipeline and a washing additive box, wherein the automatic delivery system further comprises a distribution box arranged inside the water box, the distribution box being internally provided with at least one installation cavity for accommodating a washing additive box; the washing additive box being installed in the installation cavity, the washing additive box being a closed box body with a cavity for accommodating washing additive, and being provided with a unidirectional ventilation structure and a liquid outlet, the liquid outlet being open when the washing additive box is communicated with the detergent delivery pipeline, and the liquid outlet being close when the washing additive box is disconnected with the detergent delivery pipeline; and a negative pressure extraction mechanism, comprising a Venturi tube arranged in the main water inlet pipeline, the washing additive being drawn out of the washing additive box via the detergent delivery pipeline and delivered into the washing barrel through the main water inlet pipeline by a negative pressure generated by water flow through an outlet of the Venturi tube, wherein the outlet of the main water inlet pipeline is communicated with a water outlet of the water box, wherein, the washing additive box is provided with a liquid outlet device, the liquid outlet device comprises an on-off valve arranged on the liquid outlet of the washing additive box and a suction device arranged in the washing additive box, the suction device is a hollow tubular structure, a flow channel is formed inside the suction device, and one end of the flow channel faces a bottom wall of the washing additive box, and another end of the flow channel is communicated with an inlet of the on-off valve.