A sub-pixel rendering method, comprising the following steps: acquiring a second pixel array corresponding to an original image, each sub-pixel of the second pixel array corresponding to a greyscale value; mapping the second pixel array of the original image onto a first pixel array; respectively finding the central positions of the sub-pixels of the first pixel array and of the second pixel array, determining sub-pixels of the second pixel array positioned in every sub-pixel preset region in the first pixel array and of the same colour as said sub-pixels in the first pixel array, and measuring the distance of same from the central position of said sub-pixels of the first pixel array; on the basis of the distance, calculating the proportional coefficient occupied by the sub-pixels of the second pixel array in the sub-pixels of the first pixel array, and on the basis of the proportional coefficient and the greyscale value of the sub-pixels of the second pixel array, calculating the greyscale value corresponding to each sub-pixel of the first pixel array. The preset sub-pixel rendering method is simple and easy to implement; few hardware resources are required, and software operation is rapid.