A thin film inductor includes a first magnetic thin film and a second magnetic thin film that are adjacent, the first magnetic thin film is nested in the second magnetic thin film, and a relative magnetic permeability of the first magnetic thin film is less than a relative magnetic permeability of the second magnetic thin film, and a difference between the relative magnetic permeability of the first magnetic thin film and the relative magnetic permeability of the second magnetic thin film is greater than or equal to a first threshold, where when a magnetic induction intensity of the second magnetic thin film reaches a saturated magnetic induction intensity of the second magnetic thin film, a magnetic induction intensity of the first magnetic thin film is less than or equal to a saturated magnetic induction intensity of the first magnetic thin film.