5G application achieves high speed and wide bandwidth performance (60 GHz) which needs precise impedance matching. From testing industry point of view, test interface diagnose will suffer Device under Test sensitive contact which impact impedance matching. This paper introduces an innovative methodology to measure S-parameter by Automatic Test Equipment built-in Vetor Network Analyzer without mounting external instrument. In that way ATE could automatically power up the components on test interface and leverage ATE to measure S-parameter. Engineers could finally avoid device contact. The methodology significantly enhances test setup quality and debug efficiency, improving maintenance cycle time with simple/easier process.