Embodiments of the invention provide a light spot homogenization-based beam expansion method and device, and relate to the technical field of light spot homogenization-based beam expansion. Accordingto the method, laser is firstly emitted, through a laser, to a connected optical fiber, first homogenization is carried out on the laser through the optical fiber and then the laser is transmitted toa concentration lens corresponding to an output end; the first homogenized laser is concentrated through the concentration mirror, and the concentrated first homogenized laser is transmitted to a homogenizer; and finally, second homogenization is carried out on the received first homogenized laser through the homogenizer, and the obtained second homogenized laser is transmitted to a collimation and beam expansion mirror for collimation and beam expansion, so as to convert the second homogenized laser into parallel beams for output. Through above settings, the problem that speckles and interference fringes are easy to occur in high-power laser can be improved.