A beam exposure device includes a light-emitting unit for emitting light beams from a plurality of light-emitting positions, a scan unit, an optical condensing system for condensing a spot of the light beams onto a surface to be exposed, and a micro-deflection unit for micro-deflecting the plurality of light beams to expose the space between the beams in the plurality of light beams. The optical condensing system includes a first microlens array arranged between the light-emitting unit and the micro-deflection unit and provided with a plurality of microlenses corresponding to the light-emitting positions; and a second microlens array arranged between the micro-deflection unit and the surface to be exposed and provided with a plurality of microlenses each microlens corresponding to the light-emitting unit.
