Position adjusting system and position adjusting method for large-size CT (Computed Tomography) detection equipment

The invention provides a position adjusting system for large-size CT (Computed Tomography) detection equipment. The position adjusting system comprises a detector lathe body, a ray source lathe body and a workpiece lathe body which are respectively used for mounting a detector/detector support, a ray source and a workpiece; the position adjusting system further comprises a detector adjusting device, a ray source adjusting device and a workpiece adjusting device which are respectively and correspondingly arranged on the detector lathe body, the ray source lathe body and the workpiece lathe bodyas well as a main control unit and a CT scanning position correcting device; the CT scanning position correcting device is used for simulating the geometrical relationship of rays which are transmitted and received by the ray source and the detector so as to assist the location of the detector and the ray source; the CT scanning position correcting device comprises a CT correction laser transmitting end and a CT correcti