In order to clarify the influence of the distance between laser and wire on the process of laser welding with filler wire, theoretical analysis and experimental verification on the relationship between surfacing tests and different distances of laser and wire in three laser mode have been carried out by using high-speed camera, appearance inspection, and macroscopic metallography. The data about the influence of the distance between laser and wire on the stability of welding wire melting, droplet transfer, molten pool fluctuation, and weld solidification during filler wire welding was obtained. The results show that: When the distance changes from -5mm to +5mm, the droplet transition goes through the stages of “droplet→droplet+liquid bridge→liquid bridge→droplet+liquid bridge”. With the same distance, the penetration depth of the laser mode from the largest to the smallest is respectively single-beam laser mode, dual-beam laser serial mode, and dual-beam parallel mode, and even the weld offset and no penetration appears at the same time. In addition, the single-beam mode and the dual-beam serial mode have similar effects on the wire and the molten pool, while the dual-beam parallel mode with different energy distributions has the different effect. With the increase of the defocus, the penetration depth of the weld is rapidly reduced from the maximum value of 409.8μm to 282.6μm during the single-beam laser welding. While the maximum penetration depth of the weld is only 328.4μm in the dual-beam laser serial mode, which decreases as the defocusing amount decreases, but the weld cross-section is asymmetrical at positive defocusing amount. In the dual-beam laser parallel welding mode, the weld has no penetration when the welding wire is biased to the low-power laser beam; but a small penetration weld of only 226.5μm is formed as the welding wire moves to the high-power laser beam. This research provides a reference for laser additive manufacturing and welding of aluminum alloy.