Quadratic regression orthogonal experiment was used to study the influence of different process parameters on the formability results of plasma fuse additive manufacturing. The results show that the welding speed has the greatest influence on the welding width, and the interaction between power and welding speed has the least influence on the welding width. The effect of wire feeding speed on melting height is the greatest, and the repetition of welding speed has the least effect on melting height. The interaction between power and wire feed rate has the greatest influence on aspect ratio, and the welding speed has the least influence on aspect ratio. The melting depth is mainly affected by the heat input, that is, the power. The error between the predicted value and the actual value of the quadratic regression model is less than 10%, and the predicted result is good. It is suitable for the additive manufacturing process of RT-1400 titanium alloy plasma fuse: P(welding power)= 3KW, WFS(wire feed speed)= 2.4m /min, Ts(scanning speed)=0.2m/min, welding pass spacing is 5.3mm, using interlayer orthogonal scanning mode.