Abstract: Based on the cold metal transfer arc additive manufacturing technology, AZ31 magnesium alloy single-pass samples were prepared, and the weld bead width and height of the samples were tested.According to the quadratic general rotary unitized design and the second polynomial stepwise regression analysis, the highly significant relationships between the weld bead size, i.e. width and height, and the oscillating width, welding speed, wire feed speed and substrate temperature were established.The results show that the influence of process parameters on the weld bead width is mainly in the order of oscillating width, wire feed speed, substrate temperature, and welding speed; and the degree of influence of process parameters on the weld bead height is in the order of welding speed, oscillating width, substrate temperature, and wire feed speed. As the oscillating width increases, the weld bead width gradually increases, and theweldbead heightgraduallydecreases; asthe welding speed increases, both the weld bead width and h eight gradually decrease; as the wire feed speed increases, the weld bead width and heightalso increase simultaneously; asthe substrate temperature increases, the weld bead width increases and the weld bead height decreases.