Abstract: Multi-information fusion including current, voltage and high-speed camera signals was used to investigate the effect of wire-wire distance on the arc behavior,droplet transfer and weld formation. The largest Lyapunov exponents of welding current during laser-twin-arc hybrid welding process were numerically evaluated in different wire-wire distances based on chaos theory. The results clearly demonstrate that the laser-twin-arc welding process was in chaotic state. Arc shape and droplet transfer were affected by the interactions of laser-induced plasma and arc plasma in laser-twin-arc hybrid welding process,which consequently influenced the weld formation. The largest Lyapunov exponent and its standard deviation was smallest and the welding process reached steady state in optimal wire-wire distance.