A switching converter, control method control circuit thereof are disclosed. The switching converter converts a DC input voltage into a DC output voltage. The control circuit comprising: a compensation module, generating a ramp signal; a comparator, compares a first superimposed signal related to the DC output voltage with a second superimposed signal related to an error signal between the DC output voltage and the ramp signal; a first RS flip-flop generates a pulse width modulation signal in accordance with a set signal and a reset signal, obtains a constant on time in accordance with the reset signal, and obtains an off time related to the DC output voltage; and a driving module which converts the pulse width modulation signal into a switching control signal, wherein the compensation module adaptively adjusts the slope of the ramp signal. The control circuit adopts an adaptive ramp signal to perform compensation.