A washing additive automatic delivery device for a washing machine, comprising a container for accommodating washing additive; a mounting part for holding the container, wherein the container is arranged in the mounting part in a removable manner; and at least one group of a liquid level detection structure configured to detect liquid level in the container; wherein the liquid level detection structure comprises a detection part, a conducting part connected with a circuit, and a fixed part, characterized in that one end of the detection part is inserted into the container in a sealed manner, and another end of the detection part is in contact with the conducting part to conduct the circuit when the container is placed in the mounting part, and is separated from the conducting part to disconnect the circuit when the container is taken out from the mounting part; said one end of the detection part is inserted into the container in a detachable and sealed manner from a bottom of the container through the fixed part, the fixed part is manufactured from insulating materials, at least a part of the fixed part is inserted into the container, and a height from a top end of the fixed part to the bottom of the container is a measurable lowest liquid level; wherein the detection part is wrapped in the fixed part in a sealed manner, the first end and a second end of the detection part both extend out of the fixed part; and wherein the liquid level detection structure comprises two detection parts, wherein if washing additive in the container is in contact with each of the two detection parts, the two detection parts are conducted through the washing additive, the liquid level detection structure forms a circuit pathway, and sufficient washing additive is detected; otherwise, if the washing additive in the container is not in contact with the two detection parts, the circuit between the two detection parts is disconnected, and the liquid level is low, the washing additive is needed to be supplemented. a container for accommodating washing additive; a mounting part for holding the container, wherein the container is arranged in the mounting part in a removable manner; and at least one group of a liquid level detection structure configured to detect liquid level in the container; wherein the liquid level detection structure comprises a detection part, a conducting part connected with a circuit, and a fixed part, characterized in that one end of the detection part is inserted into the container in a sealed manner, and another end of the detection part is in contact with the conducting part to conduct the circuit when the container is placed in the mounting part, and is separated from the conducting part to disconnect the circuit when the container is taken out from the mounting part; said one end of the detection part is inserted into the container in a detachable and sealed manner from a bottom of the container through the fixed part, the fixed part is manufactured from insulating materials, at least a part of the fixed part is inserted into the container, and a height from a top end of the fixed part to the bottom of the container is a measurable lowest liquid level; wherein the detection part is wrapped in the fixed part in a sealed manner, the first end and a second end of the detection part both extend out of the fixed part; and wherein the liquid level detection structure comprises two detection parts, wherein if washing additive in the container is in contact with each of the two detection parts, the two detection parts are conducted through the washing additive, the liquid level detection structure forms a circuit pathway, and sufficient washing additive is detected; otherwise, if the washing additive in the container is not in contact with the two detection parts, the circuit between the two detection parts is disconnected, and the liquid level is low, the washing additive is needed to be supplemented.