A display signal input device, comprising: a plurality of sub-image receiving modules, each of which being adapted for receiving one sub-image and outputting the received sub-image; an image stitching module, adapted for synthesizing display signals corresponding to the respective sub-images; wherein the image stitching module comprises an image stitching sequence determination module adapted for determining whether the plurality of sub-images outputted by the plurality of sub-image receiving modules are arranged in the predetermined sequence, when it is determined that the plurality of sub-images are not arranged in the predetermined sequence, the image stitching sequence determination module being adapted for arranging the plurality of sub-images into an original image according to a predetermined sequence, and the image stitching module being adapted for outputting the synthesized display signals corresponding to the plurality of sub-images in groups according to the predetermined sequence. characterised in that the image stitching sequence determination module comprises: an edge matching unit, adapted for determining whether two adjacent sub-images have matched contact edges; and a sequence adjustment unit, which is adapted for adjusting positions of the sub-images until any two adjacent sub-images have matched contact edges, when the edge matching unit determines that the two adjacent sub-images do not have matched contact edges. a plurality of sub-image receiving modules, each of which being adapted for receiving one sub-image and outputting the received sub-image; an image stitching module, adapted for synthesizing display signals corresponding to the respective sub-images; wherein the image stitching module comprises an image stitching sequence determination module adapted for determining whether the plurality of sub-images outputted by the plurality of sub-image receiving modules are arranged in the predetermined sequence, when it is determined that the plurality of sub-images are not arranged in the predetermined sequence, the image stitching sequence determination module being adapted for arranging the plurality of sub-images into an original image according to a predetermined sequence, and the image stitching module being adapted for outputting the synthesized display signals corresponding to the plurality of sub-images in groups according to the predetermined sequence. characterised in that the image stitching sequence determination module comprises: an edge matching unit, adapted for determining whether two adjacent sub-images have matched contact edges; and a sequence adjustment unit, which is adapted for adjusting positions of the sub-images until any two adjacent sub-images have matched contact edges, when the edge matching unit determines that the two adjacent sub-images do not have matched contact edges. an edge matching unit, adapted for determining whether two adjacent sub-images have matched contact edges; and a sequence adjustment unit, which is adapted for adjusting positions of the sub-images until any two adjacent sub-images have matched contact edges, when the edge matching unit determines that the two adjacent sub-images do not have matched contact edges.