A manufacturing method of a plugged honeycomb structure including attaching a transparent sheet to an end face of a honeycomb structure; picking up an image of the end face; with respect to cells positioned at other than outermost peripheral portion of a honeycomb structure (usual cells), subjecting the picked-up image to image processing, recognizing positions to be plugged on said sheet, and with respect to cells positioned at outermost peripheral portion (outermost peripheral cells), positions of the cells are recognized based on an average cell pitch calculated from the positions of the cells, subjecting to a perforation treatment based on the recognized positions of the sheet, submerging an end portion into a plugging slurry in which a material of the plugging portions is slurried, filling holes made at the respective sheet with the slurry to form the plugging portions.