Abstract: The microstructure and properties of strain-strengthened 304 austenitic stainless steel after pulse current arrest were studied. The results show that the microstructure of strain-strengthened 304 stainless steel forms a solidification zone, a recrystallization zone and a martensite zone under the action of temperature field and stress field after pulse current. With the increase of deformation, the martensite content in the martensite zone increases continuously. Moreover, the range of the heat-affected zone is furtherly expanded; at the same time, the recrystallization zone transforms from partial recrystallization into complete recrystallization. The hardness of the strain-strengthened stainless steel increases with the increase of the deformation.However, due to appearance of the solidification zone and recrystallization zone around the melting hole after pulse crack arrest,the hardness of the material at the crack stop significantly reduces, and then, the decrease of hardness can indicate the plasticity improvement to some extent,which is a advantageous to suppressing the secondary expansion of the crack.