Abstract: The butt joining of 304 stainless steel was carried out by using laser -MAG hybrid welding.The droplet transition during low speed welding and high speed welding and the morphology, microstructure and mechanical properties of the welded joints were studied.The results show that the droplet transition modes are short circuit transition and large droplet transition under low speed welding conditions.Under the condition of high speed welding, the droplet transition modes are drip transition and jet transition.The welding speed has little effect on the microstructure of the joint.In terms of tensile properties, the strength and elongation of the joint under high speed welding are significantly improved compared with that under low speed welding because of the decrease of welding heat input.