Abstract: The coordinates on the CCD image plane is regarded as star sensor's input signals. The accuracy of the inputs is affected by the inherent errors of the optical system and the CCD installation error. The method of star sensor's calibration and leading building was based on star reference frame, and it didn't depend on large expensive equipment such as swivel table and star simulator. Based on the precise celestial equator coordinates of the star observing, this method had solved the problem of the CCD installation error and made it to be a part of the optical system calibration. In a word, it is a simple and efficient method about calibration and leading building. Above all, experimental results and analysis show that the method is able to achieve the high accuracy to arc second scale.