1. An apparatus for positioning geometric model, comprising: a machine tool; a control unit, electrically coupled to the machine tool; a storage unit, electrically coupled to the control unit; a positioning module, electrically coupled to the storage unit; a virtual target geometry module, electrically coupled to the positioning module; and a virtual machine tool module, electrically and respectively coupled to the virtual target geometry module and the positioning module; wherein, the control unit is enabled to control at least one axis of the machine tool to move to a reference pose and probe a geometry while accordingly generating at least one reference pose data and at least one probing data of actual geometry; the storage unit is used for storing the reference pose data and the probing data of actual geometry; the virtual target geometry module is enabled to generate at least one data of virtual target geometry and at least one selected data of positioning of virtual target geometry; the positioning module is enabled to receive the data of virtual target geometry, the selected data of positioning of virtual target geometry, the reference pose data and the probing data of actual geometry to be used for generating a positioning data; and the virtual machine tool module is enabled to receive the positioning data, the data of virtual target geometry and the selected data of positioning of virtual target geometry to be used for generating and positioning a virtual target geometry in the virtual machine tool module; wherein the positioning module is enabled to generate a transformation matrix according to the data of virtual target geometry, the selected data of positioning of virtual target geometry, the reference pose data and the probing data of actual geometry.