For there is no regulations and standards of digital signal calibration. The design of digital measurement equipment accuracy detecting system, which uses the analog of standard power source as signal source, the NI-USB6281 precision transformer and AD conversion module to realize signal conversion, through digital SV standard table sent message, and with digital watt-Hour meter as test object, a large number of trials. According to large amounts of experimental verification, the accuracy deviation analysis of digital measurement equipment and detecting system can actualize the test of accuracy to digital measurement equipment especially the digital watt-hour meter, which is used as testing subjects, and the accuracy reaches 0.02%.This detecting system can solve the problem that digital signal can not trace to the source perfectly, and providing a method to accuracy deviation analysis of digital measurement equipment.