Abstract: During the laser-TIG hybrid process,the arc keeps stable when the welding speed increases because of the inducting and compression of laser on the TIG arc.After the removing of the coaxial shielding gas of laser,the plasma will grow with the increase of current and laser power due to the disappearance of effect of the shielding gas on laser,as a result,the section of bead is changed.By adjusting the parameters of laser and TIG the statuses of the growing plasma shot by CCD and the bead section were investigated.Through analyzing the relationship of the plasma images and the bead section,the parameters that can produce bead of wilder width and shallower penetration are acquired.These parameters can be used in superficial coating of high speed.