Three phase oil-immersed full sealed distribution transformer differs from ordinary oil-immersed transformer, it cancels oil conservator and heat-sink cooling by ripple plate radiator in oil tank, which can compensate the increase and decrease of oil volumetric by elastic breathing. All series product are suitable in 10KV, 20KV, 35KV power transmission and distribution system, can be used in residential area, commercial street, industry mining enterprises.