Abstract: Metallurgical characteristics in the electric arc furnace steelmaking process were analyzed.The result showed that energy supply played a decisive role on material transformation.On the basis of the realization of space-time multi-scale structures which contained microscale,mesoscale,unit operation and working operation scale,trans-scale integration on two units of oxygen supplying and power supplying was realized according to energy in working operation scale and a general method of energy integration was formed.Its mathematical and physical expressions could be described.Industrial test and industrial production indicated that great production efficiency was made in combination with the idea and method of trans-scale integration.The smelting electricity consumption was 271.1 kW·h·t^-1,the oxygen consumption 40.4 m³·t^-1,and the smelting period 52.9 min on average.