Abstract: In order to further study the effect of electron beam welding on nickel-based superalloy dissimilar materials, GH4169 superalloy and IC10 nickel-based single crystal superalloy were selected for the electron beam welding test. The microstructure of the electron beam welded joints was observed using metallographic microscope and scanning electron microscope, and the mechanical properties of the nickel based superalloys were analyzed. The results show that nickel-based superalloy dissimilar materials joints without obvious welding defects can be obtained through electron beam welding. The welded area is composed of dendritic and equiaxed grains, and a large number of columnar grains are enriched near the fusion area, growing perpendicular to the fusion line towards the center of the weld. After welding, the main second phase in the GH4169 and IC10 base metals is the δ-Ni₃Nb phase. After welding with an acceleration voltage of 100 kV, the average microhardness of the weld area is 235 HV, and after welding with an acceleration voltage of 150 kV, the average microhardness of the weld area is 225 HV. Under both parameters, the average microhardness of the weld zone is higher than that of the base metal zone at both ends. The closer the base metal at both ends is to the weld, the higher the hardness tends to increase due to the presence of the heat affected zone.