A multi-level over-current protection circuit includes: a signal amplification circuit configured to receive a set of detection signals and output a first signal; a comparison circuit to compare the first signal with a first reference signal and a second reference signal respectively; and a time delay counting circuit. The time delay counting circuit adjusts a first count value when the first signal is higher than or equal to the first reference signal and smaller than the second reference signal, and the time delay counting circuit activates a protection mode when the first count value reaches a first protection time delay. The time delay counting circuit adjusts a second count value when the first signal is higher or equal to the second reference signal, and activates the protection mode when the second count value reaches a second protection time delay.