Abstract: In this paper,the plasma dual-wire additive manufacturing technology is used to prepare Fe-Ni alloy for the first time.The microstructure analysis shows that the microstructure composition parallel to the substrate and perpendicular to the substrate is quite different,and the microstructure parallel to the substrate is mainly composed of equiaxed grains of different sizes and contains extremely large size grains.However,the microstructure perpendicular to the substrate direction is mainly columnar crystals,columnar crystals contain different morphology of cellular crystals,and grow perpendicular to the grain boundary.The precipitates in grain boundary and in crystal are uniformly distributed.The results of elemental analysis show that there is no element segregation and the microhardness of the sample is better than that of the sample prepared by laser selective melting.