An exposure system (10), an exposure apparatus and an exposure method are disclosed. The exposure system (10) includes: a laser unit (11), a light spot switching unit (12) and a lens unit (13); the laser unit (11) is configured for producing a laser beam; the light spot switching unit (12) is configured to direct the laser beam to travel along one of different optical paths based on a desired size of a light spot for a workpiece to be exposed so that a laser beam in correspondence with the desired size of the light spot is obtained; and the lens unit (13) is configured for altering a direction in which the laser beam is incident on the workpiece. The light spot switching unit (12) enables the laser beam to be switched between the different optical paths so as to form light spots sized in different ranges, which can satisfy different needs of workpieces with various critical dimensions. As a result, an improvement in processing adaptability to different workpieces and a significant reduction in cost can be achieved.