The influence of electromagnetic field with a low frequency on the microstructure and solute solubility of 7075 alloy produced by CREM process have been investigated. Evolution of the liquidus and solidus as well as the solidification interval are also measured. Meanwhile, the flow pattern and temperature field before and after the application of electromagnetic field is also given by numerical simulation. The forced solution mechanism of alloying agents of 7075 alloy under the effects of electromagnetic field is explained from such factors as solute equilibrium coefficient of distribution, solidification interval, flow pattern and temperature field in sump and microstructure.