Ni-based welding material has a widely application in the fabrication of the key components in nuclear power plants. Two types of welding defects,ductility-dip crack and point-like defect,in the Ni-based weld metals are investigated. Based on the calculation results by Thermo-calc with TTNi8 database,several welding wires containing different Nb and Mo contents are designed and fabricated. The results show that the room temperature strength and plasticity of the weld metals improve as the Nb or Mo content increases,which effectively reduce the ductility-dip cracks and point-like defects. Finally,Ni-based welding wire with high welding defects resistant is obtained,which can meet the use requirements for nuclear power plants.