The present disclosure provides an LED driving circuit and an LED driving method, which may be applied to a switching power supply driving circuit and a linear driving circuit. The LED driving circuit includes an adjusting tube and a driving control circuit of the adjusting tube. The adjusting tube receives an input voltage, and the driving control circuit adjusts the adjusting tube to output an output current to be expected. A reference generating circuit samples an output voltage of the LED driving circuit to obtain an output voltage sampling signal and a reference current signal corresponding to the output voltage sampling signal. A current adjusting circuit samples the output current to obtain an output current sampling signal, receives the corresponding reference current signal, and controls a conduction state of the adjusting tube according to the output current sampling signal and the reference current signal.