Abstract: The present disclosure provides a detachable cosmetic bag including a cosmetic bag main body; a plurality of inner supporting plates respectively arranged on inner sidewalls of the cosmetic bag main body; and a plurality of partition plates. Each partition plate is formed by a plurality of connecting portions and a plurality of protruding portions, a plurality of strip grooves are formed on two sides of each partition plate, two ends of each partition plate are connecting portions to enable the partition plate to be connected with the supporting grooves on the inner supporting plates and/or the strip grooves on two sides of other partition plates. The cosmetic bag provided by the present disclosure is multi-functional with an inner space that can be freely changed in combination. The lower-layer bag body is foldable, improving user experience and making it easy to carry.