An intraoral three-dimensional measuring method includes a wide range three-dimensional measurement information acquisition step (step s1) of acquiring wide range three-dimensional measurement information on a three-dimensional shape measured on a wide range in a desirable measurement range in an intraoral space; a narrow range three-dimensional measurement information acquisition step (step s2) of acquiring a plurality of pieces of narrow range three-dimensional measurement information each on a three-dimensional shape measured on a narrow range narrower than the wide range in the measurement range; and a synthetic three-dimensional information creation step (step s3) of locating the plurality of pieces of narrow range three-dimensional measurement information based on the wide range three-dimensional measurement information by use of, as a synthesis reference, intra-measurement range position information common to the wide range three-dimensional measurement information and each of the plurality of pieces of narrow range three-dimensional measurement information, to create synthetic three-dimensional information on the measurement range.