Many power systems, railway systems, large-scale petrochemical plants and enterprises have a lot of electrical equipment whose internal insulation are mostly oil-filled insulation type, and therefore, test on insulating oil dielectric strength is common and necessary. To meet the needs of the market, we have developed and produced a series of insulating oil dielectric strength testers according to national standard GB/T507-2002, industry standard DL429.9-91 and the latest Electric Power Industry Standard DL/T846.7-2004 by ourselves. This instrument, by using a single-chip microcomputer as the core, can operate in full automation with high accuracy, greatly improving work efficiency and reducing the labor intensity of workers.