Abstract: An automatic milk preparing device is provided, including a microcontroller fixed in the automatic milk preparing device for controlling the operation of same, a powder box connected with the microcontroller and provided with a powder output gate in the front of the powder box for controlling the powder to be added according to the signal from the microcontroller, a water tank connected with the microcontroller for controlling the water to be added according to the signal from the microcontroller, a stirring structure fixed under the powder output gate, connected with the water tank through a first water pipe and provided with a milk outlet at the lower part of the stirring structure, and a weight measuring structure fixed below the stirring structure and connected with the microcontroller for laying a milk bottle, weighing water and/or milk powder in the bottle and feeding the result of weight back to the microcontroller.