The effect of wire arc additive manufacturing process on the structure and properties of aluminum alloy (ZL114A) was studied by means of metallographic microscope, scanning electron microscope and electronic universal test. Compared with the traditional casting method, the structure of as-deposited WAAM ZL114A has smaller dendrite spacing, the distribution of fine Si-phase is uniform, and the chemical composition is controlled effectively. Through T6 heat treatment process, Si-phase is fully spheroidized and the second phase is dispersed on the matrix of alpha-Al. Meanwhile, the mechanical properties are significantly improved. The tensile strength, yield strength and elongation are 360MPa, 315 MPa and 7.5%, respectively. Especially, the elongation is 2.1 times than that of sand casting sample, and the tensile fracture is characterized by ductile fracture. The defects of ZL114A(WAAM) are mainly pores less than 30 μm. After heat treatment, the number of pores decreases and the size increases.