Abstract: In view of the shortcomings of the traditional short-circuit grounding method for transformer equipment in maintenance test site, a new short-circuit grounding method for transformer test is proposed in this paper. The new device developed by QC team can realize the switch between short circuit and short-circuit grounding by using the transfer switch, which effectively avoids the risk of test closure line falling, significantly improves the test efficiency, and has certain popularization and application value¹.