An experimental comparative investigation has been made of the surface quality, microstructure and mechanical properties of three different types of aluminum alloy welding wires, namely, self-made wires (1#), domestic wires (2#) and imported wires (3#) by using such testing methods as microscopy, scanning, hardness test and tensile test, etc. The experimental results show that, due to their different component ratios, impurity contents, and processing methods, 3# welding wires exhibit such excellent properties as optimum surface quality and mechanical properties, lacking of such obvious defects as cracks and scratches. Fine cracks can be found on the surface of 1# wire with fine grains uniformly distributed, thus making its surface quality and mechanical properties slightly inferior; 2# wire is characterized with such defects as pits and pittings on a rough surface, thus making it the most inferior as regard to its surface quality and mechanical properties.