Abstract: A control circuit and method for a power converter controlling adaptive voltage position comprises an adder acquiring an output voltage difference between the output voltage and the reference output voltage, a digital compensator with an Z-domain transfer function to reference to the output voltage difference to generate a pulse width control signal, regulating the least significant bits of a denominator coefficient in the Z-domain transfer function such that a load line function of the power converter is performed via control of the pulse width control signal, and a pulse modulation circuit being controlled by the pulse width control signal to generate the pulse width modulation signal to control ON/OFF of power switch of the power converter. Thus, functions of controlling the negative or positive load lines and function of variable load line required by the operation of multiphase converter can be performed easily without complicated operations.