The invention is applicable to the technical field of milk suction, and provides a milk automatic feeder and a use method of the milk automatic feeder. The milk automatic feeder comprises a suction cover and a milk suction device, wherein the suction cover and the milk suction device are in sealed connection through a milk suction hose, and the milk suction device is connected with a nipple through a first milk conveying hose. The use method of the milk automatic feeder comprises the following steps: putting the suction cover on the breast, starting the milk suction device for automatically sucking milk, wherein the milk sucked from the breast flows to a milk storage bag through the milk suction hose and the first milk conveying hose, later, milk in the milk storage bag flows to the nipplethrough a second milk conveying hose, and placing the nipple in the mouth of a baby for realizing milk suction, and thus the automatic feeding of the milk is realized. For the milk automatic feeder and the use method of the milk automatic feeder provided by the invention, the milk automatic feeder can satisfy the demand of breast feeding at any time, meanwhile, the use is convenient, the privacyof a user can be protected, moreover, the safe and sanitary demands of milk suction of the baby can be satisfied, and therefore, the actual use demands of the user are greatly satisfied.