The metallurgical effects of electric pulse acted on molten steel in the tundish of Panzhihua Steel were studied,including the element segregation improvement for casting slabs and refining crystal structure. The results show that,the equiaxed crystal ratio could be 53% to 91%,average was 66%, which was higher 45% than that without electric pulse treatment;the center segregations of C,S&P of casting slab have been significantly reduced with increasing of the electric current and the frequency of electric pulse,mechanics property of hot roiled strip was better after the treatment of EP.