In line with “a backpack for commuting and business trip” and inspired from expandable suitcases, this expandable backpack is tailored for businessmen. The concealed layer supports a zipper-triggered 26L commuting) to 32L (business trip) expansion, reducing burden on back. Two layers of storage divide areas in a reasonable way to suit the needs of business trip. The extra feature of removable buckle can turn this backpack to a handbag. A USB cable can be accessed to cellphone via a side hole or directly connected to the power bank to extend duration of use and free up hands.