The invention relates to the technical field of positioning of flange bolts of a hot gas conduit of a high temperature gas cooled reactor and particularly discloses a positioning method for the flangebolts of the hot gas conduit of the high temperature gas cooled reactor. The positioning method comprises the following steps: (1) adjusting a flange surface of the hot gas conduit of the high temperature gas cooled reactor, namely (1.1) horizontally arranging a loose flange of a hot gas conduit shell into a housing of the hot gas conduit shell in a sleeving manner; (1.2) aligning the loose flange to guide bolt holes and positioning by using three guide bolts; (1.3) adjusting the position precision of the guide bolts by utilizing arc-shaped gaskets; (2) assembling main bolts, namely (2.1) implanting guide positioning bolts to make sure that the axes of the guide positioning bolts are vertical to the flange surface; (2.2) installing the main bolts by utilizing an auxiliary supporting toolfor the bolts; (2.3) installing the main bolts in a grouping manner and detecting the perpendicularity of the axes of the main bolts and the loosen flange surface; and (3) stretching and pre-tightening the bolts. The positioning method for installing the flange bolts of the hot gas conduit of the high temperature gas cooled reactor provided by the invention is simple to operate, can be conveniently operated by a field operator and can guarantee in-place installation at a time.