Abstract: In order to improve the flexibility and path planning reliability of arc additive manufacturing, a novel arc additive manufacturing system was developed using Python based on open source slicing software Cura, with the platform of ABB IRB1410 industrial robot and Fronius CMT TPS3200 welding power supply. And 4043 aluminum alloy parts were fabricated by the system successfully. The results showed that the self developed software was reliable to read the two-dimensional path data output by the open source slicing software Cura, and convert it to identifiable controlling data of the robot. It can transfer the controlling data to the robot and control the movement of the welding torch and the operation of the welding power supply, thereby performing the wire arc additive manufacturing. A 71 layers straight wall sample and a 58 layers complex shell part were fabricated by the system with a wire of 1.2 mm diameter under the conditions of 3.2 m/min wire feeding speed, 8 mm/s welding speed, 1.65 mm layer height and 15 L/mm argon shielding gas flow rate. The results showed that solidification microstructure of the fabricated sample was a typical columnar crystal with the fine condition of overlapping between layers, and the complex shell part was complete shaped with good surface quality.