In one embodiment, a control circuit configured for an interleaved switching power supply, can include: (i) a feedback compensation signal generation circuit configured to sample an output voltage of the interleaved switching power supply, and to generate a feedback compensation signal; (ii) a first switch control circuit configured to compare a voltage signal indicative of an inductor current in the first voltage regulation circuit against the feedback compensation signal, and to control a first main power switch in the first voltage regulation circuit; and (iii) a second switch control circuit configured to turn on a second main power switch in the second voltage regulation circuit after half of a switching cycle after the first main power switch is turned on, and to regulate an on time of the second main power switch.