A method for mounting a dental cast on an articulator, comprising the steps of: providing the articulator and a label module, wherein the label module has at least one label, at least one reference object, a bite member, a positioning aid and a label carrying member, the positioning aid has said at least one reference object, one end of the positioning aid is connected with the bite member, the opposite end of the positioning aid is connected with the label carrying member, and the at least one label is fixed to the label carrying member; generating a label coordinate information in accordance with the at least one reference object and the at least one label, wherein the label coordinate information includes coordinate transfer relationships between the at least one reference object of the label module and the labels of the label module; providing a midface and mandible image information and generating a landmark coordinate information in accordance with a plurality of landmarks of the midface and mandible image information, wherein the landmark coordinate information includes coordinate transfer relationships between condyle-representative points and the at least one reference object in the midface and mandible image information; generating a structure coordinate information in accordance with a plurality of structures of the articulator and the label, wherein the structures comprise an upper arm portion and a pivot shaft of the articulator, and wherein the structure coordinate information includes coordinate transfer relationships between the labels and the pivot shaft and the labels and the upper arm portion; disposing a first dental cast connected with the label module on the articulator; providing a detecting device to detect the at least one label and adjust the position of the first dental cast in accordance with the midface and mandible image information, the label coordinate information, and the structure coordinate information, wherein the detecting device is an optical detecting device and comprises a pair of camera modules, and the label is a light-emitting diode, a pattern or a reflective member, and wherein the mandible image information includes a mandible image and position indicator images (72a, 72b); and moving the first dental cast, so as to make condyle-representative point images (711, 712) of the mandible image be overlapped with positions of the position indicator images (72a, 72b). providing the articulator and a label module, wherein the label module has at least one label, at least one reference object, a bite member, a positioning aid and a label carrying member, the positioning aid has said at least one reference object, one end of the positioning aid is connected with the bite member, the opposite end of the positioning aid is connected with the label carrying member, and the at least one label is fixed to the label carrying member; generating a label coordinate information in accordance with the at least one reference object and the at least one label, wherein the label coordinate information includes coordinate transfer relationships between the at least one reference object of the label module and the labels of the label module; providing a midface and mandible image information and generating a landmark coordinate information in accordance with a plurality of landmarks of the midface and mandible image information, wherein the landmark coordinate information includes coordinate transfer relationships between condyle-representative points and the at least one reference object in the midface and mandible image information; generating a structure coordinate information in accordance with a plurality of structures of the articulator and the label, wherein the structures comprise an upper arm portion and a pivot shaft of the articulator, and wherein the structure coordinate information includes coordinate transfer relationships between the labels and the pivot shaft and the labels and the upper arm portion; disposing a first dental cast connected with the label module on the articulator; providing a detecting device to detect the at least one label and adjust the position of the first dental cast in accordance with the midface and mandible image information, the label coordinate information, and the structure coordinate information, wherein the detecting device is an optical detecting device and comprises a pair of camera modules, and the label is a light-emitting diode, a pattern or a reflective member, and wherein the mandible image information includes a mandible image and position indicator images (72a, 72b); and moving the first dental cast, so as to make condyle-representative point images (711, 712) of the mandible image be overlapped with positions of the position indicator images (72a, 72b).