Laser-induced plume affects the process of high-power fiber laser welding. The effect of Tungsten Inert gas (TIG) arc on the plume characteristics and the welding results are investigated. An IPG YLS-6000 fiber laser and a Fronius MagicWave3000job digital welding machine are used in the experiment. The profile of the plume and the arc plasma are recorded by a high-speed camera. Furthermore, the weld depth and weld width are measured by a microscope. The fundamental law of TIG arc on plume induced in high power fiber laser welding is studied, and the main mechanism of this effect is analyzed. The results show that, the weld depth of hybrid welding significantly increases by about 20% compared with pure fiber laser welding, and almost isn′t affected by arc current. The weld width gradually improves as arc current increases. The weld depth and weld width are insensitive to the distance between laser and arc within limits. The main effect of TIG arc on plume is the gasification of the particles in plume by high temperature TIG, so the influence of plume on laser beam significantly weakened.