The present invention is applicable to the field of direct current conversion, and provides a DC-DC converter. In the present invention, a DC-DC converter including a triangular wave generation module and a switch control module is adopted. The triangular wave generation module generates a triangular wave signal according to voltages at both ends of an energy storage inductor L1, and the switch control module outputs a control level according to its internally generated clock signal and the triangular wave signal to control a switching operation of a PMOS power tube and an NMOS power tube according to a preset switching frequency.