It adopts advanced electromagnetic design software, and meets IEC60076, GB1094, GB/ T6451, GB/T25289-2010 standards. Without such device like conservator, air breather..., so it ensures that the transformer oil is not in contact with air, improving the anti-oxidation capacity of the transformer oil and delaying its aging. The core is made of high quality cold-rolled grain-oriented sillcom steel sheet, with laminated structure miter joint, so as to reduce the no-load losses and noload current. The tank is a corrugated type, the corrugated fins can swell and shrink with the change of transformer oil, so that the pressure can be maintained inside the tank, increase its reliability and anti-corrosion capability. The coil of distribution transformer, wound by high intensity enameled wrapped conductors with good AmpereTurn balance and reasonable insulation structure, has a strong short-circuit withsatand capacity. The distribution transformer adopts the free-untanking structure. With sealing material parts made of high quality acrylic rubber, it can effctively privent agianst light-aging abd heat-aging.