A coupled inductor and a power converter. The coupled inductor includes a magnetic core and at least two windings. The magnetic core includes at least two first magnetic cylinders, at least one second magnetic cylinder, and two opposite magnet yokes. The at least two first magnetic cylinders and the at least one second magnetic cylinder are disposed between the two opposite magnet yokes, the at least two windings are respectively located on the at least two first magnetic cylinders, and the at least two windings are in a one-to-one correspondence with the at least two first magnetic cylinders. Leakage inductance of the coupled inductor is increased by adding a second magnetic cylinder between the opposite magnet yokes of the coupled inductor, thereby meeting a requirement of system stability when the coupled inductor is connected to the power converter.