Abstract: In order to solve the outstanding problems of lower cladding efficiency and lower welding efficiency existing in GTA heat source additive manufacturing process, a kind of quadruple-electrode gas tungsten coupling arc double-wire additive manufacturing process was put forward in the paper, and influence of cladding current, travel speed and wire feeding speed on forming quality of single-layer and single-pass deposited layer was studied through experimental methods of controlling variables. The results showed that fluctuation of molten pool area and arc pressure were the main reasons for defects of discontinuity and edge biting in single deposited layer under quadruple-electrode gas tungsten heat source. Under the premise of ensuring forming quality, the maximum traveling speed of quadruple-electrode gas tungsten heat source was 400 mm/min, the maximum wire feeding speed was 12 m/min, and deposition efficiency was 6.24 kg/h. Microstructure of the deposited parts was composed of tempered sorbite, contravariant austenite and carbide. Impact absorbed energy of the deposited parts reached 208 J, which was 2.5 times that under MAG heat source. In summary, quadruple-electrode gas tungsten coupling arc double-wire additive manufacturing process could significantly solve problems of lower cladding efficiency and lower welding efficiency existing in GTA heat source additive manufacturing process on the premise of ensuring excellent impact performance.