The droplet transfer behavior and welding stability of 10Ni3CrMoV steel plate with 14mm thickness under single MIG and laser-MIG combined welding were compared and analyzed, and the profile morphology of welded joint was observed. The results show that under the action of low current and high current, the shape of weld profile is semi-circular at the upper end and triangular at the lower end, while the shape of laser-MIG composite weld profile is Y-shaped; there are no defects such as porosity, slag inclusion, cracks, incomplete penetration and incomplete fusion in the welded joint under the same laser-arc spacing. The penetration depth and penetration width under the action of large laser power, small current and large laser power are larger than those under the action of small laser power and small current. Moreover, the penetration depth and penetration width under the action of large laser power, small current and large laser power and large current do not show a linear change with the change of laser-arc spacing. And the influence of melting width is obviously lower than that of large laser power. Under the condition of laser-MIG hybrid welding, the suitable spacing between laser and arc is 1.5~4.5 mm, 3~4.5 mm and 1.5~3 mm respectively under the action of high laser power and small current (11 KW, 260 A), high laser power and large current (11 KW, 420 A) and low laser power and small current (7 KW, 260 A). In this range, the welding process is stable without droplet flying sputtering phenomenon, droplet transition form is a single jet transition.