Manufacturing method of tire forming mold and tire forming mold

A manufacturing method of a tire forming mold in which an annular mold portion brought into contact with at least a tread portion of a tire is constituted by a combination of sectors which are divided in a tire circumferential direction, comprising:

• a step of manufacturing a circular arc shaped inner segment present along a tire circumferential direction and provided with a concavo-convex shape corresponding to a tread pattern in an inner peripheral surface;
• a step of dividing the inner segment by a non-flat surface division so as to obtain a first segment piece and a second segment piece;
• and
• a step of incorporating the first segment piece into an inner peripheral side of a back segment of one sector out of a pair of sectors which are adjacent to each other in the tire circumferential direction, incorporating the second segment piece into an inner peripheral side of a back segment of the other sector, and arranging the non-flat surface divided surface in each end surface in a tire circumferential direction of the one sector and the other sector.