Abstract: this article introduces a bellows compression device for auxiliary replacement of transformer gas relay. This article introduces the basic functions of transformer gas relay and bellows, which are arranged in the pipeline between transformer oil tank and oil pillow, and analyzes the difficulties in the current transformer gas relay replacement and maintenance work, finally, the current maintenance work strategy on the tools and tools for technical innovation. A bellows compression device for auxiliary replacement of transformer gas relay is proposed, this auxiliary tool in the substation main transformer gas relay related test calibration, maintenance replacement a series of work to achieve effective control of work safety, work efficiency substantial improvement and work quality significantly enhanced objectives, to assist the maintenance personnel can quickly and efficiently complete the transformer gas relay replacement and related maintenance work, shorten the power outage time, for enterprises and society to create huge benefits.