The invention relates to a hot-sprue nozzle structure for accurate positioning of syringe parts. The hot-sprue nozzle structure comprises a hot runner nozzle and a thermal insulation mat, and is characterized in the hot runner nozzle comprises a hollow spherical body or cone, a hollow cylinder and a flange close to the spherical body or cone; the part, in contact with injection molding resin, of the hollow cylinder is the hollow spherical body or cone; one side, close to the end face of a resin outlet in a hot runner device, of the hot runner nozzle is provided with a first circular table; the end face of one side, close to the flange, of the thermal insulation mat butts against an inner hole corresponding to the rear end of a cavity sprue, and the end face of one side, far away from the flange, of the thermal insulation mat butts against the end face, close to one side of the flange, of the first circular table; the flange and the part of the outer contour face of the first circular table tightly butt against the inner hole corresponding to the rear end of the cavity sprue; the end face of the first circular table of the hot runner nozzle is directly and tightly fitted with the end face of a splitter plate resin outlet in the hot runner device. The hot-sprue nozzle structure has the advantages that the situation that the hot runner nozzle generates position offset due to thermal expansion of the hot runner device can be avoided, and the purpose of accurate positioning is achieved.