Magnet optical rotation assembly and optical isolator

The invention discloses a magnet optical rotation assembly. The magnet optical rotation assembly comprises at least one set of magnet ring array. The magnet ring array comprises a first magnet ring, a second magnet ring and a third magnet ring, the first magnet ring, the second magnet ring and the third magnet ring are sequentially and coaxially stacked and restrained, and the external diameter of the first magnet ring and/or the third magnet ring is adjusted to achieve adjusting of a magnetic field of the magnet ring array. According to the magnet optical rotation assembly, the first magnet ring and the third magnet ring are each composed of at least two flabellate magnetic sheets, the external diameter of the first magnet ring and/or the third magnet ring is variable accordingly, and variation of magnetic force can be adjusted by adjusting the external diameter of the first magnet ring and/or the third magnet ring. The external diameter of the first magnet ring and/or the third magnet ring is adjusted to achieve radial-direction magnetic force adjusting of the magnet optical rotation assembly, and under the condition that losses are not increased, the variation range of the magnetic force of the magnet optical rotation assembly is expanded.