Through the experiment, the reduced temperature, the containing scandium quantity of the fused salt, the agitated intensity and the restoring time that influence the rate of receives of scandium, and determined the technological conditions which uses the method of hot Al-Mg restoring anhydrous the chloride of scandium to prepare the Al-Mg-Sc master alloy. The best experimental technological conditions are that the master alloy can contains 8.0% of scandium while the restoring temperature is at 900℃, the restoring time is 20min and the agitated time is a half minute. When the method of the fused salt covered with bell, agitated and pressed the argon is used in the expansion tests, the agitated number is 4 times and the average receives rate of Sc is 90.0%.