A switching regulator has a voltage reduction module, a first acquisition module, a second acquisition module, a third acquisition module, a comparison module and a pulse width modulation module, wherein the comparison module compares a superposed signal of a flat-wave signal or a ramp signal and a feedback signal with an acquisition signal, and outputs a comparison signal; the second acquisition module outputs the ramp signal when the acquired output signal is greater than a preset value, otherwise outputs the flat-wave signal; or when the working current obtained from the main circuit is greater than a preset value, a ratio of the feedback signal output from the third acquisition module to the working current of the main circuit is 1, otherwise the ratio is less than 1. The switching regulator has the advantages of excellent transient response, quick response, and high reliability.