Toroidal-Core pole-mounted distribution transformer with high-efficiency and low-loss can be directly installed in the places nearest to electricity load, greatly convenient for the users with small power load and urban street lamp power supply in the country. This transformer has been earlier used in western countries, which gives a new sign for the users with small power load and 10/0.4kV distribution grid and proposes a new concept of distributed load power supply. The Company manufactured fully insulated 5-167kVA sealed single-phase distribution transformer with reference to ANS standard combined with the characteristics of our 10kV system and then introduced it widely to the community.