A coupled inductor and a power converter includes at least two input ends, an output end, a common magnetic core, at least two first windings, and at least two second windings. The common magnetic core includes at least two magnetic cylinders, and the number of the at least two magnetic cylinders corresponds to the number of the at least two input ends; and one first winding and one second winding are twined in parallel on each cylinder among the at least two magnetic cylinders, and the first windings and the second windings on the at least two magnetic cylinders are mutually connected between the at least two input ends and the output end to form mutually coupled inductances and when currents that flow into the at least two input ends are equal, make the first winding and the second winding on each cylinder generate opposite magnetic potentials.