The present disclosure provides a fingerprint photocurrent detection unit, a fingerprint identifier, a driving method and a display device. The fingerprint photocurrent detection unit includes: a conversion circuit coupled to a fingerprint photocurrent reading line and configured to convert a fingerprint photocurrent acquired by the fingerprint photocurrent reading line into a square wave signal; and a detection circuit coupled to the conversion circuit and configured to detect the square wave signal and acquire information about a fingerprint photocurrent in accordance with a frequency of the square wave signal.