Abstract: The embodiment of the application discloses an optical isolator, comprising an isolator main component and a magnetic field adjusting module, wherein the center of the isolator main component is provided with a central through hole; the isolator main component includes: at least a group of magnet array, a Faraday optical rotation component and a magnetic field adjusting screw disposed in the central through hole; the magnet array is disposed around the central through hole, the magnetic field adjusting module includes: a magnetic field adjusting electric motor; the magnetic field adjusting screw is connected to the magnetic field adjusting electric motor and the magnet army, respectively, the magnetic field adjusting electric motor is configured to adjust magnetic field strength applied to the Faraday optical rotation component from the magnet array by changing the displacement of the magnetic field adjusting screw.