Forced oil circulating water cooler for transformers, a cooler device specially designed for large transformer cooling systems, is a new type of optimized design based on JB/T8316-1996and other standards and drawing on similar domestic product structures Energy-efficient products. The joint of the cooling tube and the tube sheet adopts a double-ring groove process, so that the cooling tube is inserted into the groove after passing through the expansion tube to ensure that the expansion joint does not leak. The cooling pipe is made of high-quality corrosion-resistant copper pipe with high strength, no demand for water quality, wide application range, high cooling efficiency, safe and reliable use, and can be used in single or group installation.