Abstract: The element distribution character in thickness direction of continuously cast continuously rolling 10CrNiCu steel plate was studied by laser in situ analysis technology. The results show that the content of C in lower surface is higher than that of upper surface, the segregation micro zone of P and S scatter finely, Mn, Ni, Cr, Si are central positive segregation and distribute symmetrically along the center line of the steel plate, Cu is well-distributed, the relationship between segregation and radius of element atom is inverse proportional, the segregation of C is most significant, the segregation of P, S, Si are medium, the segregation of Mn, Ni, Cr, Cu are minute.