A backlight lamp bar, a backlight module and a display device are provided in embodiments of the disclosure, all being relating to a technical field of display technology, the backlight lamp bar as disclosed including: a flexible circuit board; and a backlight source and a button light source both being provided on the flexible circuit board; the backlight source and the button light source being located on two opposite faces of the flexible circuit board perpendicular to a thickness direction thereof, and power supply terminals of the backlight source and the button light source are electrically connected with circuits on the flexible circuit board, respectively.