Abstract: A conversion control circuit controls a power stage circuit of a switching power converter according to a first feedback signal and a second feedback signal, wherein the conversion control circuit includes an error amplifier circuit, a ramp signal generation circuit, a pulse width modulation circuit, and a quick response control circuit. The quick response control circuit performs a quick response control function, wherein the quick response control function includes: comparing the second feedback signal with at least one reference threshold to generate a quick response control signal; and when the second feedback signal crosses the reference threshold, adjusting a slope of a ramp signal according to the quick response control signal to accelerate an increase or decrease of the duty of a PWM signal, thereby accelerating the transient response of the switching power converter.