A method of self-detecting and dynamically displaying detected results for a card reader used to read flash memory cards includes the steps of sending out a detecting code to each card slot or any flash memory card inserted therein via detecting circuits provided on and controlled by a control chip in the card reader; storing a detected state code sent back by the detecting circuits in a state register of the control chip; sending the state code from the state register to a computer; comparing and determining the state code in the computer; displaying a current state of the card slot or the flash memory card inserted therein on a screen of the computer; and periodically repeating the self-detecting and displaying to always show the most current state of the card slots on the card reader or the inserted flash memory card.