Abstract: Based on principle of dispersion and accumulation, wire and arc additive manufacturing technology can realize rapid mold-free processing of nickel-based superalloy complex structures, which is a widely concerned advanced processing technology. In this research, high-temperature corrosion-resistant superalloy Inconel 617 additive manufactured block was used as the research object, and microstructure and mechanical properties of nickel-based superalloy additive manufactured block were analyzed by methods of OM, SEM and universal tensile testing machine. The research results showed that Mo element segregated to interdendritic zone, which promoted precipitation of large-sized Laves phases along dendrites. Under tensile stress, Laves phase was prone to fracture due to its high brittleness and then induced initiation of cracks in tensile samples. Due to significant differences in crack propagation paths when stress was applied in different directions, strength of additive manufactured components along the deposition direction (900 MPa) was significantly higher than that in the vertical deposition direction (700 MPa). The research laid a certain foundation for regulation of microstructure and mechanical properties of nickel-based superalloy by wire and arc additive manufacturing and made a useful exploration for further promoting application of wire and arc additive manufacturing nickel-based superalloy components.