Abstract: Research progress of external magnetic field and deep cryogenic treatment in aluminum alloy welding was systematically reviewed in the article. Influence of external magnetic field and deep cryogenic treatment on arc physics and macroscopic effects in the aluminum alloy welding process was emphatically analyzed,as well as its relationship with welding process. Moreover,research results of microstructure were reviewed and analyzed from different scales,such as microstructure,mechanical properties and formation mechanism. The results showed that the addition of external magnetic field changed the shape of welding arc,the mode of droplet transition and the flow of molten metal in the molten pool,and good microstructure and shape of weld could be obtained under the appropriate magnetic field parameters. After deep cryogenic treatment,the grain of aluminum alloy rotated and refined,which ultimately made the performance of deep cryogenic treatment part more excellent.This article provided some guidance for the research and application of external magnetic field and deep cryogenic treatment in aluminum alloy welding.