In order to improve the inner quality of superalloy master ingots, a technology of vacuum electromagnetic casting (V-EMC) was developed for the superalloy, i.e., applying electromagnetic stirring to the solidification process of vacuum casting. The effect of electromagnetic stirring on the inner quality of superalloy master ingots was studied with EPMA and optical microscope. The results show that the equiaxial crystals of superalloy master ingot can be effectively refined and increased, and the central shrinkage porosity and the dendritic segregation are greatly reduced, so the inner quality is obviously improved for the superalloy master ingots when electromagnetic stirring at a frequency of 50 Hz and a current of 60 A.