To ensure high-precision calibration of gear measuring instruments, the international standard ISO / TR 10064-5:2005 recommends a Double-Ball Artifact (DBA) as calibration reference. The DBA employs a high-precision sphere to replace the involute and uses an error compensation technique to obtain a high-precision involute to realize the involate traceability. The theoretical issues relating to the DBA are discussed to provide a theoretical basis for the design and application of the DBA. The error of measurement principle of DBA and its calculation function are given under the conditions of ideal installation and with installed errors for the electronic generative metrology. According to the optimized arc thoughts, the formula of the optimized center distance between the two balls is derived by the least square method. Finally, the error compensation method is described.The DBA software is designed based on the above theory and a DBA is developed with a parameter of module in 2.268 1 mm, number of teeth in 40, and a pressure angle in 20 °.