A keyboard backlight circuit integrated with a key detection function, a keyboard backlight circuit driving method, and a key input apparatus. The keyboard backlight circuit comprises a plurality of scanning lines (10) and a plurality of output lines (11); each scanning line (10) has a main line (102) and a plurality of
branch lines (103) connected in parallel with the main line (102), the main line (102) having first
voltage terminals (100), and each
branch line (103) having a second
voltage terminal (101); a light-emitting
diode (D1-D9) and a first
resistor (R1-R9) connected in series are arranged in sequence between each second
voltage terminal (101) and a connection position of each
branch line (103) with the main line (102), the light-emitting diodes (D1-D9) causing a current to be unidirectionally conducted towards the first resistors (R1-R9); each output line (11) has a voltage output terminal (110), and a plurality of switch circuits (12) connected to the plurality of scan lines (10), respectively, the switch circuits (12) being connected to portions of the scan lines (10) located between the light-emitting diodes (D1-D9) and the first resistors (R1-R9), and each switch circuit (12) comprising a
key switch (SW1-SW9). By means of arranging the switch circuits (12) in series in the keyboard backlight circuit, the functions of key detection and anti-
ghosting can be implemented while achieving a keyboard backlight effect.