The utility model discloses an oily device is got in detection of transformer, including oil retrieval pipe, movable mounting has the piston in oil retrieval pipe's the inner chamber, the right side fixed mounting of piston has the connecting rod, the right -hand member of connecting rod runs through oil retrieval pipe and pull ring fixed connection, there is one -way filling valve the lower part through first spring swing joint in oil retrieval pipe's the left side inner chamber, connector fixedly connected with straw is passed through to the lower part of one -way filling valve, there is one -way delivery valve the lower part through second spring swing joint in oil retrieval pipe's the left side inner chamber, hose and bottle lid fixed connection are passed through to the upper portion of one -way delivery valve, the downside fixedly connected with receiving flask of bottle lid. The utility model discloses simple structure, convenient and practical, when sampling, convenient to use is swift, is convenient for observe the volume that draws the sample, totally enclosed operation, the detection error of having avoided the sample to cause can the inside trouble that whether exists of real reaction transformer to in time maintain.