Abstract: Operation and operator technologies introduced by new generation Geometrical Product Specification (GPS) provide the necessary knowledge foundation for digitizing measurement of product′s geometrical error.Based on research in new generation GPS basic theory, the operator formation for obtaining the cylindrical axis factor is analyzed, which include extraction, association, construction, partition, extraction, association, collection.Moreover, the mathematical model of realization operator is presented.The whole digitizing process of obtaining the cylindrical axis factor is realized through an example.This method provides the important theory foundation for digitizing design and verification of parallelism, perpendicularity, and coaxiality in new generation GPS.