Electrical pulse technology has been researched to accelerate the sulfate attack in cement based materials under different temperatures, but the acceleration mechanism of sulfate attack by action of electrical pulse is not involved. By comparing accelerated sulfate attack by electrical pulse with conventional attack, the distribution and migration of sulfate ion under the action of electrical pulse were studied, and the microstructure of erosion product was tested by using X-ray diffraction (XRD). The test result indicated that more sulfate ion was transferred into sample by action of electrical pulse, and sulfate ion was enriched in an area within 2 cm at the cathode. The corrosion product before 28 days is ettringite and gypsum. It is concluded that the sulfate attack of cement based materials is accelerated under the action of electrical pulse by the speed migration and reaction of sulfate ion.