Abstract: Wire and arc additive manufacturing generally has problems of larger morphology error of structural parts and difficult precision control. For additive manufacturing process of aluminum alloys with weaving-gas tungsten arc welding (W-GTAW) heat source, size and morphology characteristics of additive manufactured thin walls were studied under different weaving angles and weaving left and right stop times. Compared with conventional GTAW arc additive manufacturing, W-GTAW thin-walled forming parts could obtain a smaller penetration of substrate, and the smaller weaving speed and weaving left and right stop time were, the higher thin-wall height was. When weaving speed was 3.0 × 10⁻² rad/s and weaving left and right stop time was 0.15 s, cladding height of thin-walls was 15.91 mm, second only to conventional GTAW thin-walled forming parts. For thickness of thin walls, wall thickness of W-GTAW formed part was 13.83 mm under the condition that arc weaving left and right stop time was 0.25 s, which was 2.67 mm higher than that of conventional GTAW, and tilt angle at both ends of substrate was only 0.2° under this condition. Compared with conventional GTAW additive manufacturing technology, W-GTAW obtained a thin wall with a maximum accuracy of 0.92. Under experimental conditions, dimensional accuracy of thin walls could be further improved by appropriately increasing weaving angle and weaving left and right stop time.