A processing method for a multi-row, multi-column flat lens with an equivalent negative refractive index, wherein the flat lens comprises an optical waveguide component, the optical waveguide component comprises a rectangular optical waveguide array consisting of multiple-row and multiple-column optical waveguides arranged obliquely at 45° and an edge optical waveguide placed on a periphery of the rectangular optical waveguide array, individual rectangular optical waveguides in each column and/or each row of the rectangular optical waveguide array are identical in size, characterized in that the processing method comprises: step 1: processing an optical material into a rectangular block, cutting the rectangular block into a square plate, and processing the square plate into a parallel plate having a front surface and a rear surface that are parallel to each other; step 2: taking one of the front surface and the rear surface of the parallel plate as a photolithography surface, and successively performing photoresist coating, masking and exposure on the photolithography surface, wherein unexposed blocks and exposed blocks subjected to the exposure are rectangular blocks, diagonal sides of all the rectangular blocks are respectively parallel to edges of the parallel plate, and the exposed blocks and the unexposed blocks are diagonally interlaced; step 3: removing photoresist in the unexposed blocks on the parallel plate, and forming rectangular grooves each having a depth ranging from 0.1mm to 2mm; step 4: coating surfaces of the exposed blocks and all surfaces of the rectangular grooves with a protective layer, and coating side surfaces of the rectangular grooves with a reflective film; step 5: removing the protective layer on the surfaces of the exposed block and bottom surfaces of the rectangular grooves, filling the rectangular grooves with a filling material, and further processing the front surface and the rear surface of the parallel plate in such a manner that a parallel misalignment between the front surface and the rear surface thereof is smaller than l' to obtain a new parallel plate; and step 6: adding a protective window sheet (1, 3) on each of the front surface and the rear surface of the new parallel plate. step 1: processing an optical material into a rectangular block, cutting the rectangular block into a square plate, and processing the square plate into a parallel plate having a front surface and a rear surface that are parallel to each other; step 2: taking one of the front surface and the rear surface of the parallel plate as a photolithography surface, and successively performing photoresist coating, masking and exposure on the photolithography surface, wherein unexposed blocks and exposed blocks subjected to the exposure are rectangular blocks, diagonal sides of all the rectangular blocks are respectively parallel to edges of the parallel plate, and the exposed blocks and the unexposed blocks are diagonally interlaced; step 3: removing photoresist in the unexposed blocks on the parallel plate, and forming rectangular grooves each having a depth ranging from 0.1mm to 2mm; step 4: coating surfaces of the exposed blocks and all surfaces of the rectangular grooves with a protective layer, and coating side surfaces of the rectangular grooves with a reflective film; step 5: removing the protective layer on the surfaces of the exposed block and bottom surfaces of the rectangular grooves, filling the rectangular grooves with a filling material, and further processing the front surface and the rear surface of the parallel plate in such a manner that a parallel misalignment between the front surface and the rear surface thereof is smaller than l' to obtain a new parallel plate; and step 6: adding a protective window sheet (1, 3) on each of the front surface and the rear surface of the new parallel plate.