An airflow adjustment device is disclosed. The airflow adjustment device is used for a blade server provided for plugging in an interface card, and the interface card includes a bracket. The airflow adjustment device is installed in the blade server, and the airflow adjustment device includes a top cover, a plurality of sidewalls, a bracket plate, and at least one deflector. The bracket plate is used for sheltering the bracket, and air enters the blade server through the at least one deflector and at least one gap area formed by the bracket plate and at least one of the plurality of sidewalls whereby the flow resistance of the blade server is not affected by the type of the bracket.