In order to clarify the effect of process parameters on weld formation of laser-MAG hybrid welding under full penetration state, full penetration welding process experiments at high welding speed had been carried out on 6 mm AH36 high strength steel by hybrid laser-arc welding with disc laser. The effects on the weld formation and mechanical properties of wire feeding speed、laser power、welding speed were studied. The results show that within a certain range, increasing the wire feeding speed or laser power can reduce the back hump. When the laser power is 6.5 kW, the wire feeding speed is 8 m/min, and the welding speed is 2.5 m/min, the weld formation is good and there are no welding defects. The hardness of weld metal is greater than that of the base metal. The tensile strength of the welded joint is greater than that of the base metal.