The invention relates to an improvement of a drum of a classification washing single-tub drum washing machine. When people wash clothes, they always hope that underwear and outerwear, decolorized clothes, and clothes for adults and children can be washed separately, so as to avoid cross-contamination and dyeing between clothes. However, the current single-tub drum washing machine washes one type of clothing first and then washes another type of clothing, which not only wastes water, electricity and time, but also requires manual intervention in the middle, which brings inconvenience to users. In the present invention, a detachable partition 22 is added in the single-tub drum 21, and the inner space of the single-tub drum 21 is divided into two independent washing spaces with different sizes on the left and right (the front and rear can also be separated), and different kinds of clothes can be placed at the same time Wash in 2 independent washing spaces, and take off the partition 22 when you need to wash bulky clothes. Among the figure, two of 25 are the washing ribs that the top is provided with grooves and are sealingly connected with the cylinder inwall, 23 and 24 are washing ribs, and 27 is a water level sensor.