A 10 kW fiber laser was used to conduct the experimental study on laser-arc hybrid welding with 10 mm AH36 marine steel in this paper. Which was also compared with MAG welding on the same material, and was analyzed from aspects of weld molding, weld section morphology, welded joint mechanical properties, welding deformation, efficiency and cost. The results show that MAG welding and laser-arc hybrid welding both can acquire good weld molding and cross-section morphology by selecting the appropriate wire feeding speed, and the weld strength is also greater than the base material. The deformation of laser-arc hybrid welding is only about 50% of MAG on the same thickness and length welds.The welding efficiency advantage of laser-arc hybrid welding is more obvious, which can be 5 times as much as MAG welding. The welding material cost of hybrid welding is only 21% of MAG welding, gas cost is about 42% of MAG welding, the difference of equipment cost is becoming smaller with the same efficiency. In the long run, the advantage of laser-arc hybrid welding is much greater than MAG welding.