Portable pen bag

The utility model discloses a carry-on pen bag which comprises a pen bag body and an expansion bag, and the pen bag body is of a bag body structure with an open top. The multifunctional pen bag has the beneficial effects that the plurality of expansion bags are arranged on the front surface of the pen bag body in a joint manner, and are respectively provided with the storage bins, so that a nurse can conveniently classify and properly place other tools carried by the nurse respectively in a manner that the plurality of expansion bags are additionally arranged on the front surface of the pen bag body; the use functions of the pen bag body are enriched, and meanwhile, nurses can conveniently use the pen bag body in daily life; the heights of the bag openings of the plurality of expansion bags in the front of the pen bag body are sequentially reduced from inside to outside, so that the top bag openings of the pen bag body and the plurality of expansion bags can be obviously exposed, and portable tools placed in