Detergent supply device for rotary drum washing machine

The present invention discloses a detergent supply device of drum washing machine. It includes the following two portions: detergent tank in which the detergent is held and control panel on which a detergent tank hole through which the detergent tank can be put in or taken out is formed. It is characterized by that on two side surfaces of said detergent tank two transverse U-shaped opposite left and right guide ribs are formed respectively, and said left and right guide ribs can be plugged in along the front and back direction, and on two sides of the above-mentioned detergent tank hole formed on the control panel two opposite transverse U-shaped left and right guide grooves are formed, so that said structure can make the detergent tank be firmly combined together with said control panel.