Dynamic annular laser spot generation method and device

The invention discloses a dynamic annular laser spot generation method and device, and belongs to the field of medium and low power laser welding. The device sequentially comprises a laser, a light beam collimation unit, an acousto-optic modulator, a light beam focusing unit and an annular optical fiber in the light path direction. The laser is used for generating an incident laser beam, and the incident laser beam is collimated by the light beam collimation unit to form a collimated laser beam; the acousto-optic modulator is used for enabling the collimated laser beam to generate Bragg diffraction to obtain 0-level diffracted light and 1-level diffracted light; the zero-level diffraction light and the first-level diffraction light are coupled into an inner fiber core and an outer fiber core of the annular optical fiber after being focused by the light beam focusing unit and are totally reflected in the inner fiber core and the outer fiber core, and then annular light spots are generated. According to the met