A lithography illumination system comprising: a laser light source, a collimating and expanding unit, a pupil shaping unit having an exit pupil plane, a first micro-lens array having a back focal plane and being composed of multiple identical first micro-lenses, and each of the first micro-lenses having a field angle, a second micro-lens array having a front focal plane and a back focal plane, and being composed of multiple identical second micro-lenses, and each of the second micro-lenses having a field angle, a condenser lens group, a mask, a micro-scanning slit array, a motion control unit, and a micro-integrator rod array having an entrance end surface and an exit end surface, and being composed of multiple identical micro- integrator rods; wherein the lithography illumination system is arranged such that a beam emitted from the laser light source passes sequentially through the collimating and expanding unit, the pupil shaping unit, the first micro-lens array, the micro-integrator rod array, the micro-scanning slit array, the second micro-lens array, and the condenser lens group, and illuminates the mask; the motion control unit is connected to the micro-scanning slit array for controlling a moving speed and distance of the micro-scanning slit array to scan a light field; the first micro-lens array is located at the exit pupil plane of the pupil shaping unit; the entrance end surface of the micro-integrator rod array is located at the back focal plane of the first micro-lens array; the exit end surface of the micro-integrator rod array is located at the front focal plane of the second micro-lens array; the back focal plane of the second micro-lens array and the mask are a pair of conjugated planes of the condenser lens group; and each of the first micro-lenses, the micro-integrator rods, and the second micro-lenses are in one-to-one correspondence. a laser light source, a collimating and expanding unit, a pupil shaping unit having an exit pupil plane, a first micro-lens array having a back focal plane and being composed of multiple identical first micro-lenses, and each of the first micro-lenses having a field angle, a second micro-lens array having a front focal plane and a back focal plane, and being composed of multiple identical second micro-lenses, and each of the second micro-lenses having a field angle, a condenser lens group, a mask, a micro-scanning slit array, a motion control unit, and a micro-integrator rod array having an entrance end surface and an exit end surface, and being composed of multiple identical micro- integrator rods; wherein the lithography illumination system is arranged such that a beam emitted from the laser light source passes sequentially through the collimating and expanding unit, the pupil shaping unit, the first micro-lens array, the micro-integrator rod array, the micro-scanning slit array, the second micro-lens array, and the condenser lens group, and illuminates the mask; the motion control unit is connected to the micro-scanning slit array for controlling a moving speed and distance of the micro-scanning slit array to scan a light field; the first micro-lens array is located at the exit pupil plane of the pupil shaping unit; the entrance end surface of the micro-integrator rod array is located at the back focal plane of the first micro-lens array; the exit end surface of the micro-integrator rod array is located at the front focal plane of the second micro-lens array; the back focal plane of the second micro-lens array and the mask are a pair of conjugated planes of the condenser lens group; and each of the first micro-lenses, the micro-integrator rods, and the second micro-lenses are in one-to-one correspondence.