By the hybrid technique of fiber laser and variable polarity tungsten inert gas, A7N01 aluminum alloy is welded with filler wire. After optimizing process parameters, joints with good formation and without defects are obtained. The microstructure, tensile and fatigue properties of these joints are investigated, and the fatigue-fracture characteristic and fracture morphology are examined. The research results indicate that these joints are mainly composed of fine-grained zone, columnar grains, and equiaxed dendrites. The average tensile strength of these as-welded joints is 320 MPa, around 75% of that of base metals. After natural aging of 30 days, the average tensile strength increases to 369 MPa, around 83% of that of base metals. Fractures locate at the stress concentration zone of the weld toe, and the fracture shows an obvious dimple shape, which is the unique characteristic of ductile fracture. The fatigue limit of these joints is 115 MPa.