Many factors affect the quality of the overlap joint in the laser brazing process, such as laser power, welding speed, defocusing distance and so on. The influences of wire feeding speed on the overlap joints′ mechanical properties are studied. The results indicate that a large number of dispersed phases are found in the overlap joint, which is identified as Fe-Si(Cu). These phases appear as granular, island or petal shape. A joint with best mechanical property is got when the wire feeding speed is 2.0 m/min. Phases of Fe-Si(Cu) distribute densely in the joint. The mechanical properties of the overlap joint is best, and is higher than that of the base metal. The fracture occurs in the base metal. When the wire feeding speed is 1.7 m/min and 2.3 m/min, phases of Fe-Si(Cu) only sporadics distribute in the joint. The mechanical properties of the overlap joint is worse than that of the base metal. The fractare occurs at the brazing seam. The fracture mode is the ductile and brittle mixed fracture.