The 220kV three-phase oil-immersed on-load tap-changing power transformer has undergone a series of major reforms in materials, processes, and structure. It features small size, light weight, high efficiency, low loss, low noise, and reliable operation, significantly reducing grid losses and operating costs, resulting in substantial economic benefits. It is suitable for power plants, substations, and large factories and mines. This product conforms to the national standards: GB1094.1-2013 “Power Transformers Part 1: General Rules”, GB1094.2-2013 “Power Transformers Part 2: Temperature Rise”, GB1094.3-2003 “Power Transformers Part 3: Insulation Level, Insulation Test and External Insulation Air Gap”, GB1094.5-2003 “Power Transformers Part 5: Short Circuit Withstand Capacity”, and GB/T6451-2015 “Technical Parameters and Requirements for Three-Phase Oil-Immersed Power Transformers”.