To deal with the lack of information for coordinate measurement of three-dimensional model and the difficulty of quality evaluation of task-specific coordinate measuring results, the computer aided design method for coordinate measuring technology based on the secondary development of CATIA system was presented, according to the new gengration Geometrical Product Specifications (GPS). The XML data structure for integration of CAD and CMM was designed. The extended data model used UML technology for coordinate measurement was established. The scripted description of measurement process meeting the requirements of new generation of GPS was achieved. Some algorithms for measurement data processing were developed. And method and process of measurement uncertainty evaluation based on Monte Carlo simulation were proposed. Based on the above methods, the special software for three dimensional CAD-based computer aided design and assessment was developed and applied in pose measurement for assembly of aircraft parts. The results indicated that the measurement plan generated by the special software meets the requirements of part docking in aircraft flexible assembly, thus the effectiveness of the method was verified. 