The application provides a step-down circuit and power management device, belongs to analog circuit technical field. The step-down circuit includes: the device comprises a voltage input end, a voltage output end, a voltage reduction module and a control module; the step-down module includes: a plurality of switching components, a first capacitor, a second capacitor, and an inductive element; the first end of the first switch component is connected with the voltage input end, the second end of the first switch component is connected with the first end of the third switch component, the second end of the third switch component is connected with the first end of the fifth switch component, and the second end of the fifth switch component is connected with the voltage output end; the output end of the control module is connected with the control end of each switch component respectively. The method and the device can reduce complexity of the circuit system by adopting fewer circuit elements, and can reduce voltage of a power supply circuit on the portable and wearable electronic equipment with smaller volume.