A portable storage device is provided. A housing has a first opening and a second opening. A storage body has a connector and a pair of positional restriction structures. The storage body slides in the housing to make the connector extend outside the housing or hide in the housing via the first opening. A pair of actuating arms is provided in the housing and can swing. An actuating structure is partially exposed outside the housing via the second opening and pivotally connected to the pair of actuating arms. An elastic element is connected to the actuating structure and the storage body, so that the elastic element pushes the storage body and drives the actuating arms to return to the original position to block the positional restriction structures.