Abstract: The single-pass multi-layer arc additive manufacturing tests of 4043 aluminum alloy were conducted under preset weld pass width of 8mm and different interlayer waiting times. The effects of interlayer waiting time on the appearance,microstructure and mechanical properties of the arc additive parts were investigated with the help of metallurgical microscope and universal testing machine. The results show that the interlayer waiting time is a key factor for the height of weld channel,the side surface roughness of weld channel and thickness uniformity. When the interlayer waiting time is 20-30s, the appearance forming quality is good and the tensile properties are optimal. With the increase of interlayer waiting time, the grain gradually refines. When the interlayer waiting time is 0-30 s, the hardness shows a distribution of low in the middle and high at the bottom and top. When the interlayer waiting time is 40 s, the hardness shows a decreasing trend from the bottom to the top.