Abstract: The influence of different process parameters on the microstructure and hardness of the deposited layer by Fe-Co-Ni-Cu powder core wire arc additive manufacturing was studied. The best arc cladding process parameters were obtained to get the cladding layer with good metallurgical bonding and good performance. Through the comprehensive analysis, the optimal arc deposition process parameters are deposition current of 210 A, wire feeding speed of 140 cm/min,welding speed of 160 mm/min. The morphology of the deposited layer is flat and smooth, the dilution rate is almost, 16.62%.The average microhardness of the deposited layer is 329.1 HV, the tensile strength is 473.8 MPa, the wear resistance is 1 time higher than that of the base material. The typical microstructure from the bonding zone to the surface layer of the deposited layer is sequentially plane crystal, cellular crystal and cellular dendrite. With the increase of the welding current, the structure becomes coarse; with the increase of wire feeding speed and welding speed, the structure gradually becomes fine.