The effects of the composition and the fusion behavior of welding wires and welding-wire-related parameters on the laser welding process are summarized. With appropriate process parameters and under the condition that the continuous and smooth transition of the filler wire is ensured, a stable welding process can be realized, welding defects can be avoided, and a substantial increase of laser welding quality and weld performance can be obtained. In order to keep the laser welding with filler wire to be of intelligence, high efficiency and high quality, it is necessary to do further research on the multi-objective optimization of the interconnected process parameters, the precise control of the composition of the filler wire, the precise control and optimization of the wire-heating energy and the welding-wire temperature.