Laser double-wire MIG arc hybrid welding has the characteristics of large weld penetration, high metal deposition rate and good welding quality, however, the underlying interaction is so complicated that it brings some difficulties in the practical applications. A coupling mechanism between two arcs and laser-induced plasma is proposed based on the electromagnetic field theory. When the difference between the Lorentz force and electric field force generated by the two arcs acting on the electrons in the middle part of the laser-induced plasma is significant, the electron distributions at two ends of plasma are not uniform, which causes one arc bend, the driving force to be reduced along the wire axis, and the droplet transfer become more difficult. When the two force are balanced, the electron distributions at two ends are relatively uniform, and the plasma can attract and stabilize the two arcs, which results in a smooth droplet transfer. Laser double-wire MIG arc hybrid welding process is experimentally studied by using the high speed photography system and signal acquisition system, and the results show that when the welding process parameters are not suitable, the arc severely deviates from the wire axis so that unstable globular transfer and short circuiting transfer occur. In contrast, when the welding process parameters are suitable, the roots of the two arcs are fixed to the bottom of laser-induced plasma and a smooth and directional spray metal transfer with low spatter loss is achieved.