For huge mass and size of 1000kV(UHV) transformers, it is hard to be transported to substation, especially in mountain areas. The disassembled transformer is manufactured to reduce the difficulties and cost of long distance transportation with bridge reconstruction, road widening, rent of special vehicles. Field assembling conditions are often worse than those in factories, which becomes threaten to the quality of assembling. It is necessary to test the quality of assembled 1000kV transformers on site. No-load and Short circuit tests are considered as the effective method to test the flaws of iron core, magnetic shielding, winding conductivity. However, conducting those tests were rare and difficult for demands of power source, sophisticated system and inflexibility on site. For those, this paper introduces the main techniques and equipment research details for 1000kV transformers field no-load and short circuit tests being conducted.