Hastelloy is widely used in the aerospace industry for its excellent performance. Hastelloy X surface is modified by high-current pulsed electron beam (HCPEB) bombardment and its microstructure is analyzed and discussed. The sample after corrosion was observed by a scanning electron microscope (SEM), and the unetched sample was observed by electron backscattered diffraction (EBSD). The results show: The grain boundary of the untreated sample was corroded from the SEM micro-morphology. After the bombardment, there was a remelted layer of about 2μm on the surface of the sample. The sample possessed good corrosion resistance and granular carbides appeared at the grain boundary; It can be seen that the grain size of the sample was the smallest in 5 times of bombardment, and the grain orientation of the sample is better in 5 and 10 times of bombardment, mostly [101] and [110]. Experiments show that high-current pulsed electron beam bombardment can cause the remelted layer on the surface of Hastelloy X and change its grain size and crystal orientation.