In recent years, digital measurement devices have been widely used in Smart Substation, but its operational reliability and stability is poor, which restricts the popularization and application of digital metering device. In this paper, aiming at the problem of the error caused by the digital measuring device stability is poor. The proposed digital measuring device integrated error with electronic transformer and digital power meter test and synchronous single error error influence quantity adjustable error stability test method, set up the digital metering error and stability test system. Through theoretical analysis, experimental verification and field test, provides an effective solution to ideas and methods for analyzing and processing device error stability digital measurement, has the guiding significance for the design, manufacture and digital measurement equipments to improve the operation level.