A shape measurement method for a tire comprising: an outer surface shape measurement step in which the outer surface of a tire is irradiated with a slit light, a slit light irradiation portion of the outer surface is photographed by a first camera, and, from the image data of the photographed light irradiation portion of the outer surface, an outer surface shape data of the tire is detected; an inner surface shape measurement step in which the inner surface of the tire is irradiated with a slit light, a slit light irradiation portion of the inner surface is photographed by a second camera, and, from the image data of the photographed light irradiation portion of the inner surface, an inner surface shape data of the tire is detected; an outer surface primary component extraction step in which irregularities along the tire circumferential direction around the tire in the outer surface shape data obtained in the outer surface shape measurement step are subjected to Fourier transformation to take out a primary waveform component; an inner surface primary component extraction step in which irregularities along the tire circumferential direction around the tire in the inner surface shape data obtained in the inner surface shape measurement step are subjected to Fourier transformation to take out a primary waveform component; a circumferential position adjustment step in which the tire circumferential positions of the waveform component of the outer surface shape data and the waveform component of the inner surface shape data which have been taken out are adjusted to adjust the tire circumferential positions of the outer surface shape data and the inner surface shape data, wherein the tire circumferential positions of the waveform component of the outer surface shape data and the waveform component of the inner surface shape data are adjusted using a bead toe as a reference; a cross section position adjustment step in which, from information about the placement angles and the positions of the first camera and the second camera, the tire radial direction cross section positions of the outer surface shape data and the inner surface shape data are adjusted; and a shape data synthesis step in which, based on the adjusted tire circumferential positions and the tire radial direction cross section positions, the outer surface shape data and the inner surface shape data are synthesized. an outer surface shape measurement step in which the outer surface of a tire is irradiated with a slit light, a slit light irradiation portion of the outer surface is photographed by a first camera, and, from the image data of the photographed light irradiation portion of the outer surface, an outer surface shape data of the tire is detected; an inner surface shape measurement step in which the inner surface of the tire is irradiated with a slit light, a slit light irradiation portion of the inner surface is photographed by a second camera, and, from the image data of the photographed light irradiation portion of the inner surface, an inner surface shape data of the tire is detected; an outer surface primary component extraction step in which irregularities along the tire circumferential direction around the tire in the outer surface shape data obtained in the outer surface shape measurement step are subjected to Fourier transformation to take out a primary waveform component; an inner surface primary component extraction step in which irregularities along the tire circumferential direction around the tire in the inner surface shape data obtained in the inner surface shape measurement step are subjected to Fourier transformation to take out a primary waveform component; a circumferential position adjustment step in which the tire circumferential positions of the waveform component of the outer surface shape data and the waveform component of the inner surface shape data which have been taken out are adjusted to adjust the tire circumferential positions of the outer surface shape data and the inner surface shape data, wherein the tire circumferential positions of the waveform component of the outer surface shape data and the waveform component of the inner surface shape data are adjusted using a bead toe as a reference; a cross section position adjustment step in which, from information about the placement angles and the positions of the first camera and the second camera, the tire radial direction cross section positions of the outer surface shape data and the inner surface shape data are adjusted; and a shape data synthesis step in which, based on the adjusted tire circumferential positions and the tire radial direction cross section positions, the outer surface shape data and the inner surface shape data are synthesized.