A method of manufacturing a guide stent of a dental implant, comprising: a first step of obtaining a three-dimensional image of periodontal tissue in a mouth of a patient through an CT scan and of obtaining a three-dimensional exterior image corresponding to the three-dimensional image through an oral scan of the mouth of the patient; a second step of matching the three-dimensional image and the three-dimensional exterior image by overlapping the three-dimensional image and the three-dimensional exterior image and obtaining a three-dimensional procedure guide image therefrom; and a third step of manufacturing a stent body having a through hole corresponding to a preset implant implantation position according to the obtained three-dimensional procedure guide image; characterized in that matching the three-dimensional image and the three-dimensional exterior image in the second step includes matching through a difference map which overlaps the three-dimensional image and the three-dimensional exterior image and outputs a matching degree between the overlapped images for each pixel; obtaining the three-dimensional procedure guide image comprises a step of setting a common portion of the three-dimensional image and the three-dimensional exterior image as a comparative area, and a step of compensating for each image so that uppermost portions (1b, 2b) and outermost portions (1c, 2c) of the comparative area coincide with each other in the overlapped three-dimensional image and three-dimensional exterior image; the step of setting the comparative area comprises a step of dividing and outputting the matching degree between the images with color, and a step of designating and inputting a portion, of which the matching degree is lower than a preset matching degree in the comparative area, as an error area, and wherein the step of compensating for the three-dimensional exterior image is performed within the range of the error area. a first step of obtaining a three-dimensional image of periodontal tissue in a mouth of a patient through an CT scan and of obtaining a three-dimensional exterior image corresponding to the three-dimensional image through an oral scan of the mouth of the patient; a second step of matching the three-dimensional image and the three-dimensional exterior image by overlapping the three-dimensional image and the three-dimensional exterior image and obtaining a three-dimensional procedure guide image therefrom; and a third step of manufacturing a stent body having a through hole corresponding to a preset implant implantation position according to the obtained three-dimensional procedure guide image; characterized in that matching the three-dimensional image and the three-dimensional exterior image in the second step includes matching through a difference map which overlaps the three-dimensional image and the three-dimensional exterior image and outputs a matching degree between the overlapped images for each pixel; obtaining the three-dimensional procedure guide image comprises a step of setting a common portion of the three-dimensional image and the three-dimensional exterior image as a comparative area, and a step of compensating for each image so that uppermost portions (1b, 2b) and outermost portions (1c, 2c) of the comparative area coincide with each other in the overlapped three-dimensional image and three-dimensional exterior image; the step of setting the comparative area comprises a step of dividing and outputting the matching degree between the images with color, and a step of designating and inputting a portion, of which the matching degree is lower than a preset matching degree in the comparative area, as an error area, and wherein the step of compensating for the three-dimensional exterior image is performed within the range of the error area.