The invention discloses a mould structure provided with an eliminating splicing line. The mould structure comprises a mould, wherein the mould is provided with a mould clamping plane, the mould clamping plane of the mould is sunken inward to form a splicing cavity, a splicing piece is mounted in close fit in the splicing cavity of the mould, and a contact part of the splicing piece and the splicing cavity of the mould forms a splicing line; a mould cooling water circuit is formed in the interior of the mould, and a conformal cooling water circuit communicated with the mould cooling water circuit is formed in the interior of the splicing piece; the mould clamping plane of the mould is sunken at a splicing line position and a groove is formed, the groove is in central symmetry relative to the splicing line, the groove comprises a small groove and a big groove arranged above the small groove, the small groove is arranged between the edge of the splicing piece and the edge of the mould, the big groove is arranged between the edge of the splicing piece and the edge of the mould, and the big groove and the small groove are communicated. The mould structure disclosed by the invention can avoid influence of the splicing piece on apparent quality of an injection moulded plastic part, and the conformal cooling water circuit also can be introduced for optimizing cooling efficiency of the splicing piece.