The complete expression of pointing calibration model (PCM) for the axis related errors (ARE) of the radio telescope is derived directly. The definition of the common axis related parameters in both pointing correction model of ARE and Lösler's indirect model (IM) is unified, then the relationship between PCM and IM of the radio telescope is established. Thus, the deflection of the vertical (DOV) determination of VLBI stations is realized by using radio telescope azimuth axis information. As a direct surveying approach, this method does not rely on special DOV surveying equipment. It could only depend on pointing calibration surveying data for telescope aperiodic maintenance and the local surveying data including leveling. Verified by a variety of DOV surveying methods, the DOV obtained by our method shows a good agreement with real surveyed DOV in west-east component. Owing to the non-uniform distribution of the radio sources sky coverage of the station during its pointing calibration, the north-south component of DOV has the same direction as the surveyed DOV, but has a difference in value. In the future, further providing an optimized telescope pointing calibration, the high precision surveying of DOV will be obtained by using VLBI telescope azimuth axis
