It is studied That preparation of Al-Sc alloy by molten salt electrolysis In this text.MF-ScF3-ScCl3 as the electrolyte and ScCl3 as raw material,the processing condition of preparation of Al-Sc alloy which include the influence of current density,electrolysis hour and temperature of electrolysis on EMF,content of Sc in alloy and current efficiency.With electrolysis hour prolonged,the current efficiency increases gradually,which it can reach to the maximum of 73% and the content of Sc in alloy which can reach to the maximum of 3.85%.