A protection circuit with variable current level limits is coupled to between a power supply system and a load. The power supply system outputs power to drive the load. The protection circuit with variable current level limits of the present invention comprises: a current level limiting switch unit which is coupled to between the power supply system and the load to conduct the output power, a detection unit which detects the current value of the output power, a current level setting unit which sets a normal-state current level limit and a transient-state current level limit according to the current value of the output power, a current level setting unit which checks the current value of the output power and controls the current level limiting switch unit to limit the current value and a timer unit.